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The intersection of Human Immunodeficiency Virus (HIV) infection and cardiovascular disease (CVD) represents a significant area of concern; advancements in antiretroviral therapy (ART) have notably extended the life expectancy of people living with HIV (PLWH), concurrently elevating the prevalence of chronic conditions such as CVD. This paper explores the multifaceted relationship between HIV infection, ART, and cardiovascular health, focusing on the mechanisms by which HIV and ART contribute to increased cardiovascular risk, including the promotion of endothelial dysfunction, inflammation, immune activation, and metabolic disturbances. We highlight the critical roles of HIV-associated proteins—Tat, Nef, and gp120—in accelerating atherosclerosis through direct and indirect pathways that exacerbate endothelial damage and inflammation. Additionally, we address the persistent challenge of chronic inflammation and immune activation in PLWH, factors that are strongly predictive of non-AIDS-related diseases, including CVD, even in the context of effective viral suppression. The impact of ART on cardiovascular risk is examined, with particular attention to the metabolic implications of specific ART regimens, which can influence lipid profiles and body composition, thereby modifying CVD risk. The therapeutic potential of statins, aspirin, and emerging treatments such as PCSK9 inhibitors in mitigating cardiovascular morbidity and mortality among PLWH is discussed, alongside considerations for their use in conjunction with ART. Our review underscores the necessity for a comprehensive, multidisciplinary approach to cardiovascular care in PLWH, which integrates vigilant cardiovascular risk assessment and management with HIV treatment. As we navigate the evolving landscape of HIV care, the goal remains to optimize treatment outcomes while minimizing cardiovascular risk, ensuring that the gains in longevity afforded by ART translate into improved overall health and quality of life for PLWH. [ABSTRACT FROM AUTHOR]

Cervical cancer (CC) remains a prevalent malignancy and a significant global public health concern, primarily driven by persistent human papillomavirus (HPV) infections. The infectious nature of HPV underscores the preventability of CC through vaccination and screening programs. In addition to HPV, factors such as age, parity, smoking, hormonal contraceptives, and HIV co-infection elevate the risk of CC. HIV-associated immunodeficiency exacerbates susceptibility to infections and cancers, making CC a defining condition for acquired immune deficiency syndrome (AIDS) and one of the most commonly diagnosed cancers among women living with HIV (WLWH). These women face higher risks of HPV exposure due to sexual behavior and often encounter economic, social, and psychological barriers to screening. HIV and HPV co-infection can potentially accelerate CC carcinogenesis, with WLWH typically being diagnosed with CC earlier than their HIV-negative counterparts. Antiretroviral therapy (ART), which reduces AIDS-related mortality, also lowers the risk of invasive CC. The interaction between HIV and HPV is intricate and bidirectional. This summary reviews current evidence on HPV infection and CC in WLWH, highlighting the connections across pathogenesis, prevention, diagnosis, and treatment. [ABSTRACT FROM AUTHOR]

The present study describes the case of a 33-year-old male patient, who was diagnosed with concurrent infections of Rhodococcus hoagii (R. hoagii), Mycobacterium intracellulare (M. intracellulare), human immunodeficiency virus (HIV) and syphilis. This patient, a homeless farm laborer with no prior medical treatments, exhibited symptoms including persistent fever and cough, and was admitted to hospital. Treatment was initiated with a combination of anti-retroviral therapy with emtricitabine/tenofovir alafenamide/dolutegravir, and antibiotics (azithromycin, rifampicin, amikacin and ethambutol) targeted at both R. hoagii and M. intracellulare, alongside adjustments for drug-drug interactions due to rifampicin administration. Despite initial improvements and discharge after 21 days with scheduled outpatient follow-ups, the patient did not return for further treatment monitoring. The case presented herein underscores the challenges in managing complex infections in severely immunocompromised patients and highlights the need for integrated treatment approaches, careful drug management, and robust follow-up systems to ensure adherence and prevent relapse. In addition, the present case report contributes to the limited literature available on R. hoagii infections in HIV-infected individuals and highlights the need for early intervention and comprehensive management in similar clinical scenarios [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has revealed a diverse spectrum of clinical manifestations in the pediatric population, including the rare but notable presentation of unilateral parotitis. This comprehensive review explores the complexities surrounding SARS-CoV-2-associated unilateral parotitis in children. It addresses the initial clinical presentation, diagnostic challenges, treatment strategies, and the wider epidemiological impacts of this unusual symptom. The review synthesizes the available literature, providing insights into the pathophysiological mechanisms underlying this atypical manifestation and its implications for pediatric healthcare during the pandemic. Through the rigorous analysis of reported cases, this study underscores the need for increased awareness and a broad differential diagnosis among clinicians. It also emphasizes the importance of continued research to delineate the full clinical spectrum of COVID-19 in children. [ABSTRACT FROM AUTHOR]

Despite significant advances in the management of antiretroviral therapy (ART), leading to improved life expectancy for people living with HIV (PLWH), the incidence of non-AIDS-defining cancers, including breast cancer, has emerged as a critical concern. This review synthesizes current evidence on the epidemiology of breast cancer among HIV-infected individuals, highlighting the potential for an altered risk profile, earlier onset, and more advanced disease at diagnosis. It delves into the molecular considerations underpinning the relationship between HIV and breast cancer, including the role of immunosuppression, chronic inflammation, and gene expression alterations. Additionally, it examines the complexities of managing breast cancer in the context of HIV, particularly the challenges posed by ART and anticancer agents' cross-toxicities and drug–drug interactions. The review also addresses survival disparities, underscoring the need for improved cancer care in this population. By identifying gaps in knowledge and areas requiring further research, this review aims to illuminate the complexities of HIV-associated breast cancer, fostering a deeper understanding of its epidemiology, molecular basis, and clinical management challenges, thereby contributing to better outcomes for individuals at the intersection of these two conditions. This narrative review systematically explores the intersection of HIV infection and breast cancer, focusing on the impact of HIV on breast cancer risk, outcomes, and treatment challenges. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) has been chiefly linked with substantial respiratory complications. However, emerging studies have brought attention to the occurrence of severe muscle inflammation (myositis) related to COVID-19, potentially leading to multi-organ failure and increased mortality. Myositis is generally characterized by heightened serum creatine kinase (CK) levels. Acute myositis is characterized by an infiltration of viruses into calf muscle fibers, which may cause a subsequent inflammatory response leading to calf muscle pain. Symptomatic and supportive management, along with explanation and reassurance, is all that is required in managing this condition. While the association between myositis and severe outcomes has been recognized in adults, it remains less understood in the pediatric population. The current retrospective study, conducted at Policlinico San Marco University Hospital in Catania, aimed to analyze clinical and laboratory factors associated with myositis in pediatric patients with SARS-CoV-2 infection. Between January 2022 and January 2023, ten pediatric patients diagnosed with myositis and SARS-CoV-2 infection were evaluated. The study highlighted clinical manifestations such as fever, calf muscle pain, and abnormal gait. Lab results showed elevated CK levels among other findings. All patients underwent treatment, with the majority recovering without complications. A notable correlation was observed between CK levels, blood urea nitrogen (BUN), and the urea/creatinine ratio (UCR). The study also discusses potential pathophysiological mechanisms behind SARS-CoV-2's impact on skeletal muscles, emphasizing an indirect inflammatory response. Our findings underscore that while myositis in children with SARS-CoV-2 infection appears to follow a benign and self-limiting trajectory, it is crucial to monitor specific markers for early intervention and management. Further research is warranted to elucidate the underlying mechanisms and improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Plasmodium falciparum (P. falciparum) malaria continues to pose a significant threat to public health worldwide, particularly in endemic areas. While the majority of cases can be effectively treated and cured, recurrences of P. falciparum malaria are not uncommon and can occur years following initial exposure. This phenomenon adds a new level of complexity to the management and prevention of the disease. The present study describes the compelling clinical case of a patient who contracted malaria despite not having been in an endemic region for over a decade. The patient had previously been infected and treated for the same disease. With low parasitemia, the patient was successfully treated with anti-malarial drugs; however, certain aspects of his medical history remained unclear. The present study also discusses the possibility that this case represents P. falciparum recrudescence or cryptic malaria, drawing on existing literature to contextualize the findings. The case presented herein highlights the need for continued vigilance in the diagnosis and treatment of P. falciparum malaria, particularly in instances of recurrence. Furthermore, it underscores the ongoing challenges posed by this persistent and insidious disease. [ABSTRACT FROM AUTHOR]

In 2000, a massive die-off resulted in a drastic reduction of the guanaco (Lama guanicoe) population of Cabo Dos Bahías Reserve, Chubut, Argentina. This event became an emblematic example of guanaco population dynamics in which it is presumed that the lack of regulatory mechanisms induced a population excess that damaged forage resources to an extreme that the population crashed due to starvation. Although this case poorly represents the relevant ecological scenarios, it has a disproportionate influence on current debates regarding the management of guanaco populations. Some authors even claim that, unless guanaco populations are culled, this degradation process will propagate across Patagonian rangelands. In this paper we aimed to synthetize the available evidence and to socialize the results obtained after 15 years following guanaco and vegetation dynamics at Cabo Dos Bahías to contribute to the discussion on the causes and consequences of mentioned guanaco die-off. The available evidence shows that population density is compatible with forage availability and it is coupled with its inter-annual variability. Range condition at the reserve is similar or better, upon the indicator considered, than range condition at neighbouring ranches with traditional livestock management. Our analysis indicates that, although Cabo dos Bahías presented high guanaco densities, which fluctuated more than other populations, there is no evidence to support the lack of regulation, population excess or environmental damage. Finally, we discuss our results in the context of the current debate about guanaco management in Patagonia. [ABSTRACT FROM AUTHOR]

Although legionellosis represents a widely underestimated disease for various reasons, the rate of Legionella pneumophila infections has increased steadily over the past 30 years. The present study describes the characteristics of patients hospitalized due to legionellosis. The present study retrospectively reviewed 10 cases of legionellosis during the defined period and documented the epidemiological and clinical characteristics of the patients, as well as the methods used for diagnosis and therapeutic management. The majority of the patients were male (80%) with a mean age of 55.8 years. The most common comorbidities were hypertension (40%) and tumors (20%). Fever was present in all the cases (100%) and the most frequent imaging finding was lung consolidation. Half of the cases exhibited hyponatremia, 40% of them had leukocytosis, and 50% of the patients presented elevated procalcitonin levels, as well as elevated levels of transaminases. In total, 2 patients (20%) required non-invasive oxygen support. All the cases presented a positive urinary antigen test for Legionella pneumophila serogroup 1. A total of 9 patients (90%) received levofloxacin-based therapy for a mean duration of 17.7 days. All the cases described herein were successfully discharged without any complications. On the whole, the present study demonstrates that a prompt clinical diagnosis along with early testing and treatment represent the cornerstone for positive outcomes in patients affected by Legionnaire's disease. [ABSTRACT FROM AUTHOR]

An Eulerian walk (or Eulerian trail) is a walk (resp. trail) that visits every edge of a graph G at least (resp. exactly) once. This notion was first discussed by Leonhard Euler while solving the famous Seven Bridges of Königsberg problem in 1736. But what if Euler had to take a bus? In a temporal graph (G , λ) , with λ : E (G) → 2 [ τ ] , an edge e ∈ E (G) is available only at the times specified by λ (e) ⊆ [ τ ] , in the same way the connections of the public transportation network of a city or of sightseeing tours are available only at scheduled times. In this paper, we deal with temporal walks, local trails, and trails, respectively referring to edge traversal with no constraints, constrained to not repeating the same edge in a single timestamp, and constrained to never repeating the same edge throughout the entire traversal. We show that, if the edges are always available, then deciding whether (G , λ) has a temporal walk or trail is polynomial, while deciding whether it has a local trail is NP -complete even if τ = 2 . In contrast, in the general case, solving any of these problems is NP -complete, even under very strict hypotheses. We finally give XP algorithms parametrized by τ for walks, and by τ + t w (G) for trails and local trails, where t w (G) refers to the treewidth of G . [ABSTRACT FROM AUTHOR]

Stenotrophomonas maltophilia (S. maltophilia) is a difficult‑to‑treat bacteria. This glucose non‑fermenting, multidrug‑resistant Gram‑negative bacillus is known to cause a range of infections, such as skin manifestations and bacteraemia, with respiratory tract infections being the most common. Patients in intensive care units are often exposed to a higher risk of acquiring an infection caused by this pathogen. Although distinguishing between S. maltophilia infections and colonization can be challenging, pneumonia caused by S. maltophilia infection is becoming increasingly prevalent. Furthermore, S. maltophilia infections are often coupled with Pseudomonas aeruginosa infections, reinforcing the need to consider this bacterium as a potential cause of ventilator‑associated pneumonia (VAP). The present study describes the case of a 66‑year‑old male who was diagnosed with VAP due to S. maltophilia infection. This condition was effectively treated with trimethoprim/sulfamethoxazole. The case described herein underscores the importance of prompt recognition through heightened clinical suspicion, particularly in patients with VAP who are unresponsive to broad‑spectrum β‑lactam antibiotics. The early identification of S. maltophilia as the root cause of respiratory tract infections can make a significant difference to the outcomes of affected patients. [ABSTRACT FROM AUTHOR]

This article discusses a case of Elephantiasis nostras verrucosa (ENV), a rare condition that occurs as a complication of chronic nonfilarial lymphedema. The case involves a 68-year-old Italian woman who had ENV develop as a late complication of limb amputation. The article describes the clinical and histological features of ENV, as well as the unique dermoscopic vascular pattern observed in this case. Treatment options for ENV are also discussed, including weight loss, lymphedema alleviation measures, and surgical debridement. The article concludes by highlighting the need for further research to improve the diagnosis of ENV using noninvasive procedures like dermoscopy. [Extracted from the article]

Although the mortality rate among individuals diagnosed during the pre-Highly Active Antiretroviral Treatment era has been substantial, a considerable number of them survived. Our study aimed to evaluate the prevalence of HIV long-term survivors in a cohort of People Living with HIV diagnosed between 1985 and 1994 and to speculate about potential predictive factors associated to long survival. This is a retrospective single-center study. Subjects surviving more than 300 months (25 years) from HIV diagnosis were defined as Long Term Survivors. Overall, 210 subjects were enrolled. More than 75.24% of the included people living with HIV were males, with a median age of 28 years (IQR 25–34). The prevalent risk factors for HIV infection were injection drug use (47.62%), followed by unprotected sex among heterosexual individuals (23.81%). Ninety-three individuals (44.29%) could be defined as LTS with a median (IQR) survival of 333 (312–377) months. A hazard ratio of 12.45 (95% CI 7.91–19.59) was found between individuals who were exposed to Highly Active AntiRetroviral Treatment (HAART) and individuals who were not, with the latter being at greater risk of death. The availability and accessibility of effective antiretroviral therapy for people living with HIV remain the cornerstone of survival. [ABSTRACT FROM AUTHOR]

Understanding competitive interactions is essential to properly inform management strategies, in particular in the context of livestock‐wildlife conflict across a degraded land, such as the case of wild guanacos in Patagonia. Guanacos are historically perceived by ranchers as livestock's main competitors, and there is a growing demand for reducing their numbers. However, both competition theory and available evidence suggest a more complex interaction than the one assumed by the current management approach. This study aimed to test the occurrence of competitive exclusion of guanacos by domestic sheep at intra‐ranch scale. We assessed the spatial segregation of guanacos and sheep and compared guanaco occupancy patterns within a sheep ranch with those recorded within an adjacent protected area free from livestock. The probability of a group of herbivores being sheep instead of guanacos increased in bottom valleys and smaller paddocks and decreased as the distance to water increased. These results agree with the expected patterns of sheep habitat use resulting from physiological restrictions and grazing behaviour. Occupancy patterns within the ranch showed a higher proportion of guanacos in ridges, away from water sources and in larger paddocks, opposing those observed in the sheep‐free area where guanacos occupied mostly bottom valleys, irrespective of the distance to water. Areas used consistently by guanacos showed a higher per cent cover of preferred forage and basal‐plant cover, indicating a better range condition than those used predominately by sheep. Our results add to the solid body of evidence on spatial segregation of these species at coarser spatial scales, support the competitive exclusion of guanacos by sheep and suggest that intra‐ranch coexistence is possible because guanacos occupy areas underused or inaccessible to sheep. Under these conditions, it is unlikely that guanaco culling will improve sheep production and the empirical verification of the assumptions underlying current management initiatives becomes crucial. [ABSTRACT FROM AUTHOR]

Bacterial prostatitis infections are described as infections that are difficult-to-treat, due to prostate anatomic characteristics along with clinical difficulty in terms of diagnosis and management. Furthermore, the emergence of multidrug resistant (MDR) bacteria, such as extended-spectrum beta-lactamase (ESBL) producer Escherichia coli, also representing the main causative pathogen in prostatitis, poses major problems in terms of antibiotic management and favorable clinical outcome. Oral fosfomycin, an antibiotic commonly used for the treatment of uncomplicated urinary tract infections (UTIs), has been recently evaluated for the treatment of bacterial prostatitis due to its favorable pharmacokinetic profile, its activity against MDR gram-positive and gram-negative bacteria, safety profile, and multiple synergic effect with other antibiotics as well as the low resistance rate. This review addresses fosfomycin pharmacokinetics and pharmacodynamics and discusses the latest clinical evidence on its clinical use to treat acute and chronic bacterial prostatitis in hospitalized patients and in outpatients. As described in several reports, oral fosfomycin may represent a valid therapeutic option to treat susceptible germs commonly causing prostatitis, such as E. coli and other Enterobacterales as well as Enterococcus faecium, even as a first-line regimen in particular clinical settings (patients with previous treatment failure, with allergies or outpatients). Stronger data from further studies, including randomized controlled trials, would be helpful to establish the proper dosage and specific indications. [ABSTRACT FROM AUTHOR]

Acute and chronic bacterial prostatitis are considered infections which are cumbersome to treat, due to the limited available selection of effective antibiotics and the pharmacologically poor distribution in prostatic tissue. Furthermore, the emergence of novel antimicrobial resistance patterns, such as extended spectrum β‑lactamase (ESBL)‑producing Escherichia coli (E. coli) along with increasing fluoroquinolone resistance poses major clinical concerns in selecting the appropriate therapy to treat and eradicate the infection, particularly considering the outpatient setting. The present study describes the case of a healthy male affected by a first acute bacterial prostatitis episode due to ESBL‑producing E. coli. The patient was successfully treated with oral fosfomycin‑trometamol administration, achieving clinical success with microbiological eradication. The case described in the present study, along with the literature review, encourage and suggest the use of oral fosfomycin for the treat‑ ment of both acute and chronic prostatitis, particularly for outpatients and for those subjects who cannot be administered other antibiotics. [ABSTRACT FROM AUTHOR]

Almost 2 years have passed since the World Health Organization declared a pandemic state for severe acute respi‑ ratory syndrome coronavirus 2 infection. The pathogenesis of coronavirus disease 2019 (COVID‑19) consists of an initial viral phase responsible for early symptoms followed by an inflammatory phase, which is cytokine‑mediated, responsible for late‑onset symptoms, culminating in acute respiratory distress syndrome. Considering that IL‑6 plays a key‑role in the development and maintenance of inflammation, drugs targeting both IL‑6 and IL‑6 receptors have been evaluated. The present study reports the cases of four hospitalized patients with severe respiratory COVID‑19 treated with a single dose of sarilumab, a monoclonal anti‑IL‑6 antibody, along with standard of care medications and oxygen therapy. A few days following sarilumab administration, the clinical and biochem‑ ical conditions began to improve, until the discontinuation of O2 therapy and discharge. The present study demonstrates that sarilumab may represent a promising drug that may be used to treat the hyperinflammatory phase; however, further trials are required to determine whether it should be used combina‑ tion with other drugs or alone, and to better understand the pharmacokinetics and related side‑effects. [ABSTRACT FROM AUTHOR]

Bacterial infections, especially those in hospital settings, represent a major complication of COVID-19 patients, complicating management and worsening clinical outcomes. Corynebacterium striatum is a non-diphtheric actinobacterium that has been reported as being the causative agent of several different infections, affecting both immunocompetent and immunocompromised patients. Recently, C. striatum has been recognized as a nosocomial pathogen that is responsible for severe infection in critical patients, as well as in fragile and immunocompromised subjects. C. striatum has been described as the etiological agent of bacteremia, central line infections, and endocarditis. We report a case of a 91-year-old woman who was hospitalized due to SARS-CoV-2 infection, who developed C. striatum bacteremia and died despite antimicrobial therapy and clinical efforts. Furthermore, we discuss C. striatum diagnosis and treatment based on evidence from the scientific literature. [ABSTRACT FROM AUTHOR]

Two years have passed since WHO declared a pandemic state for SARS-CoV-2 infection. COVID-19 pathogenesis consists of a first viral phase responsible for early symptoms followed by an inflammatory phase, cytokine-mediated, responsible for late-onset manifestations up to ARDS. The dysregulated immune response has an outstanding role in the progression of pulmonary damage in COVID-19. IL-6, through the induction of pro-inflammatory chemokines and cytokines, plays a key role in the development and maintenance of inflammation, acting as a pioneer of the hyperinflammatory condition and cytokine storm in severe COVID-19. Therefore, drugs targeting both IL-6 and IL-6 receptors have been evaluated in order to blunt the abnormal SARS-CoV-2-induced cytokine release. Sarilumab, a high-affinity anti-IL-6 receptor antibody, may represent a promising weapon to treat the fearsome hyperinflammatory phase by improving the outcome of patients with moderate-to-severe COVID-19 pneumonia. Further prospective and well-designed clinical studies with larger sample sizes and long-term follow-up are needed to assess the efficacy and the safety of this therapeutic approach to achieve improved outcomes in COVID-19. [ABSTRACT FROM AUTHOR]

The use of immune suppressive drugs combined with the natural immune suppression caused by SARS-CoV-2 can lead to a surge of secondary bacterial and fungal infections. The aim of this study was to estimate the incidence of superinfections in hospitalized subjects with COVID-19. We carried out an observational retrospective single center cohort study. We enrolled patients admitted at the "Garibaldi" hospital for ≥72 h, with a confirmed diagnosis of COVID-19. All patients were routinely investigated for bacterial, viral, and fungal pathogens. A total of 589 adults with COVID-19 were included. A total of 88 infections were documented in different sites among 74 patients (12.6%). As for the etiology, 84 isolates were bacterial (95.5%), while only 4 were fungal (4.5%). A total of 51 episodes of hospital-acquired infections (HAI) were found in 43 patients, with a bacterial etiology in 47 cases (92.2%). Community-acquired infections (CAIs) are more frequently caused by Streptococcus pneumoniae, while HAIs are mostly associated with Pseudomonas aeruginosa. A high rate of CAIs and HAIs due to the use of high-dose corticosteroids and long hospital stays can be suspected. COVID-19 patients should be routinely evaluated for infection and colonization. More data about antimicrobial resistance and its correlation with antibiotic misuse in COVID-19 patients are required. [ABSTRACT FROM AUTHOR]

Heart infections are not limited to infectious endocarditis. In fact, prosthetic vascular graft infections are among the most severe complications associated with vascular and cardiac surgery. The risk of developing an infection on prosthetic material is estimated to be ~5%. The mortality rate associated with the infection is estimated to be ~10-25% within 30 days of infection and 50% after 1 year. The present article describes a case of a methicillin-sensitive Staphylococcus aureus (MSSA) infection on the prosthetic material following a heart Fontan procedure. To the best of our knowledge, only one other case of extracardiac prosthesis-related infection following Fontan surgery has been reported to date in adults. Prosthetic vascular graft infections (PVGIs) are a rare complication of heart surgery. However, PVGIs can seldomly occur and are burdened by a decreased survival rate. Therefore, physicians need to promptly suspect and recognize such cases. Further studies are required however, in order to determine the feasibility and long-term survival rates of a conservative therapeutic approach. [ABSTRACT FROM AUTHOR]

Patients with sickle cell disease (SCD) are more susceptible to severe coronavirus disease 2019 (COVID‑19) infection, in comparison with the general population, due to the possibility that the inflammatory state, along with hypoxia and hypercoagulability may increase the risk of developing acute SCD‑related complications. The present study reports the case of a 33‑year‑old female affected by SCD, who although vaccinated against COVID‑19, tested positive for SARS‑CoV‑2 and developed febrile pneumonia. During hospitalization, the patient complained about generalized intense pain, along with fever recurrence and increased inflammatory marker, procalcitonin and haemoglobin S levels. The patient was treated with an intravenous analgesic therapeutics cocktail in combination with red blood cell manual exchange procedure and broad‑spectrum antibiotic therapy, achieving the rapid resolution of pain and an improvement in the laboratory test results. From the case presented herein, it is thus suggested that patients with SCD and COVID‑19 infection need to be critically evaluated by clinicians, as such patients may develop severe outcomes, attributed to the overlap of two difficult to treat conditions. [ABSTRACT FROM AUTHOR]

A temporal graph is a pair (G , λ) where G is a simple graph and λ is a function assigning to each edge time labels telling at which snapshots each edge is active. As recently defined by Mertzios, Molter and Zamaraev (2021), a temporal coloring of (G , λ) is a sequence of colorings of the vertices of the snapshots such that each edge is properly colored at least once. We first focus on t-persistent and t-occurrent temporal graphs. The former (resp. the latter) are temporal graphs where each edge of G stays active for at least t consecutive (resp. not-necessarily consecutive) snapshots. We study which values of t make the problem polynomial-time solvable. We also investigate the complexity of the problem when restricted to temporal graphs (G , λ) such that G has bounded treewidth. [ABSTRACT FROM AUTHOR]

Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) has been shown to increase the risk of thrombotic events due to a hypercoagulable state caused by several factors. The case of a 59-year-old woman affected by hypertension and metabolic disorders, treated for a COVID-19 infection who developed cardiac symptoms during the first days of hospitalization is reported. Electrocardiogram analysis and cardiac-ultrasound confirmed ST-segment elevation myocardial infarction (STEMI) diagnosis, thus the patient underwent percutaneous coronary intervention, which was successful. This case highlights a possible association between respiratory infection, particularly SARS-CoV-2 infection, and cardiovascular events, in particular Acute Coronary Syndrome. The association between these phenomena seems related to a range of factors, including a proinflammatory state and the hypoxemia. Moreover, the association amongst SARS-CoV-2 and cardiovascular diseases may be also linked to long-term sequelae. Thus, further studies are required to better understand the multifaceted and severe complications of this disease. [ABSTRACT FROM AUTHOR]

This document is a response letter to an article proposing a new protocol for sonographic assessment of the optic nerve sheath diameter (ONSD). The authors of the response letter express their interest in the idea but provide some comments and concerns. They suggest that the ultrasound B scan technique used in the original article may not be suitable for detecting ONSD changes and mention the blooming effect as a factor that could influence the reliability of measurements. They also discuss the importance of measuring ONSD in primary gaze position and recommend using standardized A scan for more precise and reliable images. The authors conclude by stating that no conflicts of interest exist. [Extracted from the article]

Background: The rise of multi-drug-resistant Gram-negative bacteria necessitates the development of new antimicrobial agents. Cefiderocol shows promising activity by exploiting bacterial iron transport systems to penetrate the outer membranes of resistant pathogens. Objectives: This study evaluates the efficacy of cefiderocol testing methods and trailing effect impact using a ComASP® Cefiderocol panel, disk diffusion (DD), and MIC test strips (MTS) compared to iron-depleted broth microdilution (ID-BMD). Methods: A total of 131 Gram-negative strains from clinical samples was tested by commercial methods and the gold standard. Results were interpreted as per 2024 and 2023 EUCAST guidelines. Results: ID-BMD revealed high cefiderocol susceptibility among Enterobacterales and Pseudomonas aeruginosa, with one Klebsiella pneumoniae isolate being resistant. Acinetobacter baumannii exhibited higher MIC values, particularly considering trailing effects that complicated MIC readings. ComASP® showed 97% categorical agreement (CA) and 66% essential agreement (EA) with ID-BMD for Enterobacterales but failed to detect the resistant K. pneumoniae. DD tests demonstrated variable CA (72% or 93%), and 38% or 34% of strains within the ATU according to EUCAST Breakpoint Tables v13.0 and 14.0, respectively, with major errors only. MTS for P. aeruginosa had 100% CA but 44% EA, and often underestimated MIC values. Conclusions: The study emphasizes the need for standardized criteria to address trailing effects and ATU and highlights the discrepancies between testing methods. While cefiderocol resistance remains rare, accurate susceptibility testing is crucial for its effective clinical use. The findings suggest that current commercial tests have limitations, necessitating careful interpretation and potential supplementary testing to guide appropriate antibiotic therapy. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection usually affects the respiratory system; however, a number of atypical manifestations of this disease have also been reported, especially in children. The present study reports a case of a 12-year-old presenting with right unilateral parotitis and sialadenitis and SARS-CoV-2 infection. The young patient, after a 3-day history of fever, was brought to our clinic (Polyclinic University Hospital 'G. Rodolico', Catania, Italy) for the sudden onset of unilateral parotitis accompanied by sialadenitis and hyperaemia of the skin, which was tender to touch. The SARS-CoV-2 molecular swab was positive; the ultrasound of the affected region showed an increase in the volume of the parotid and sublingual gland and reactive lymph nodes compatible with parotitis and sialadenitis. This case suggests that, in the present Coronavirus disease 2019 pandemic, SARS-CoV-2 should be included in the differential diagnosis of parotitis and sialadenitis along with mumps and flue. Notably, a respiratory panel and serology for other potential causes are needed in case of parotitis-like disease. [ABSTRACT FROM AUTHOR]

The management of antiretroviral therapy is intricately associated with the evaluation of the viral genetic profile, a process in which infectious disease specialists play a pivotal role in both the selection and fine-tuning of treatment protocols. The V179D aminoacidic variation within the reverse transcriptase of the human immunodeficiency virus (HIV), while not considered among major mutations, carries the potential to exert a notable effect on resistance to antiretroviral agents. Notably, this influence extends specifically to the class of non-nucleoside reverse transcriptase inhibitors, suggesting that the presence of the V179D mutation may diminish the susceptibility of the virus to certain antiretroviral drugs within this classification. The present study describes the case of a patient which delineates the management trajectory of an HIV-positive individual, commencing from the initial diagnosis in November, 2017. A genotypic resistance test revealed the presence of the V179D mutation. Of note, notwithstanding the existence of this mutation, the patient underwent a transition to a cabotegravir and rilpivirine injectable combination regimen, resulting in a favorable treatment response characterized by comprehensive and sustained viral suppression, coupled with enhancements in the immunological profile. The case described herein underscores the critical significance of a tailored approach in the management of HIV, wherein therapeutic strategies are adeptly tailored to the unique exigencies of people living with HIV. [ABSTRACT FROM AUTHOR]

In a recently published paper, Oliva et al. concluded that domestic grazing pressure across Patagonian rangelands approached carrying capacity due to decades of stock adjustment, but that guanaco overpopulation may have altered that balance. The authors argued that unless guanaco numbers are controlled, they will reduce forage available for domestic stock and will negatively affect rangelands. We consider that the herbivore‐stock analysis presented is inaccurate and deserves revision, and that the stated conclusions lack empirical support.When the spatial distribution of herbivores is accounted for in the Oliva et al. analysis, domestic stock is far above carrying capacity, indicating that domestic overgrazing continues.Theoretical and empirical evidence on bottom‐up regulation and competitive exclusion challenges the supposed guanaco overpopulation and the hypothetical reduction of forage available for livestock.Even if guanaco numbers are reduced, grassland degradation and production losses will continue because their main drivers, domestic overstock and heterogeneous grazing, are still operating.Synthesis and applications. Oversimplified models with poor ecological insight can lead to erroneous conclusions and misguide management decisions. The incorrect inference that Patagonian domestic stock is adjusted to carrying capacity could help to consolidate current domestic overgrazing by reducing incentives to improve livestock management practices. Regarding guanacos, a controversial species in an unfavourable context, control‐oriented harvest without a clear justification threatens populations' viability and genuine attempts of productive diversification. Addressing relevant ecological processes, such as niche partitioning, competitive exclusion and population regulation, is essential to correctly assess joint carrying capacity in multi‐herbivore systems, as well as to identify the true factors driving degradation processes and to optimize rangeland use on a sustainable basis. [ABSTRACT FROM AUTHOR]

Objective: Unusual clinical course. Background: Patients with HIV infection tend to have poor intensive care unit (ICU) outcomes; however, survival in the modern combination antiretroviral therapy (cART) era has markedly improved, but Pneumocystis jirovecii pneumonia (PJP) still remains a preeminent cause of respiratory failure in AIDS patients. Extracorporeal membrane oxygenation (ECMO) is an adapted cardiopulmonary bypass circuit for temporary life support for patients not responding to conventional treatment. Case Report: A 43-year-old male HIV "late presenter" was admitted to our hospital for fever and dyspnea. A chest CT scan revealed bilateral ground-glass opacities. Empiric antibiotic treatment and cART were started. The emergence of ARDS due to PJP dictated urgent veno-venous (VV) ECMO placement. One week later, radiologic findings and respiratory function had improved and the patient was started on a weaning trial from ECMO and removed 12 days after placement. Conclusions: Acute respiratory distress syndrome (ARDS) is a potentially reversible clinical syndrome with a high mortality rate. ECMO is a rescue therapy allowing lung recovery during acute processes and should be considered an adequate treatment option in HIV+ patients with respiratory failure. ECMO should be considered a useful and adequate treatment option in AIDS patients who have a high risk of dying from respiratory failure. [ABSTRACT FROM AUTHOR]

Background: A large number of central nervous system impairments occur in subjects with chronic HCV infection regardless of liver disease. Brain-derived neurotrophic factor (BDNF) plays an essential role in the adult brain concerning its development and proper functioning. Our study aimed at contributing to the discussion on the involvement of BDNF in neurocognitive disorders associated with HCV infection. Objectives:Weaimedto evaluate the prevalence of neurocognitive disorders in a cohort of HCV-infected subjects, to measureserum BDNF levels in the same cohort according to the degree of neurocognitive disorders, and to evaluate serum BDNF level modification in HCV-infected patients after direct antiviral agents (DAA) therapy. Methods:We enrolled patients scheduled for DAA therapy in January 2018 from three infectious disease units in Eastern Sicily. Each participant was evaluated for neurocognitive status with MoCA score at baseline and 12 and 24 weeks after the end of therapy. Moreover, we measured serum BDNF levels at baseline and 12 weeks after the end of therapy. Results: Of 70 HCV-infected patients, 42 (60%) were males. The average age was 57 - 19 years and the average ALT level was 79 - 24 UI/mL; 38 (54.3%) individuals had HCV genotype 1 infection and 23 (32.8%) and 25 (35.7%) individuals had F1 and F2 fibrosis stages, respectively. Moreover, 67 (95.7%) individuals achieved sustained virological response. The MoCA score at baseline identified four groups of patients. Higher MoCA scores 24 weeks after the end of therapy highlighted the improvement of neurocognitive status in all groups. Serum BDNF levels in the same four groups, measured 12 weeks after the end of DAA therapy, appeared significantly modified compared to baseline serum BDNF levels, matching the improvement of MoCA score results obtained 24 weeks after DAA therapy. Conclusions: The serum BDNF level may represent a useful marker of cognitive dysfunction in patients with HCV infection and a useful index for assessing the post-therapy follow-up. [ABSTRACT FROM AUTHOR]

The impact of exports on productivity is a central theme in macroeconomics, explored in both the ‘learning by exporting’ and ‘Kaldor-Verdoorn law’ literature. We utilize a novel dataset of Italian firm microdata to build an empirical model examining the effect of persistent exporting on firm productivity. The model endogenizes a firm's export propensity using a probit specification that enables us to derive consistent estimates of the impact of exporting on productivity. In addition, we use the share of highly educated workers as a proxy of human capital to test the ability of persistently exporting firms to learn. This impact is derived using a biprobit specification, which enables us to endogenize the joint probability of being a continuously exporting firm while highly endowed with a skilled workforce. The results strongly support the hypothesis that persistent exporters show a significant productivity premium compared to occasional exporters. Moreover, the workforce's education level further increases productivity, with results supporting the hypothesis that highly educated shares of a firm's workforce enhance the ability to learn. [ABSTRACT FROM AUTHOR]

Finally, we question the selection of healthy eyes because the authors used 57 eyes from 30 patients and did not select both eyes from every healthy patient. 10.1038/s41598-021-88250-3. 33903644 3 De Bernardo M., Altieri V., Coppola A., Gioia M., Rosa N. Choroidal evaluation in patients under alpha-lytic therapy. 30619654 6 De Bernardo M., Cione F., Capasso L., Coppola A., Rosa N. A formula to improve the reliability of optical axial length measurement in IOL power calculation. [Extracted from the article]

ChT measurements have been checked in several diseases[2],[3] but we have some concerns about the reliability of the measurements obtained in this paper. Andrea Valerio Marino, Marco Gioia, Ludovica Reda, Aniello La Marca Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Salerno, Italy Correspondence: Ludovica Reda, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana" University of Salerno, via S. Allende, Baronissi, Salerno, 84081, Italy, Tel +39 089672407, Email [email protected] View the original paper by Dr Moleiro and colleagues A Response to Letter has been published for this article. Dear editor We read with great interest the article by Moleiro et al[1] concerning peripapillary and subfoveal choroidal thickness (ChT) in case of retinal vein occlusions. [Extracted from the article]

Previous studies on guanacos have reported that only territorial males create and maintain dung-piles. The aim of this analysis was to compare dung-pile use by territorial males with the use by females and young in family groups, and by bachelor males. Although territorial males showed the highest dung-pile use, all individuals dropped feces on piles frequently, in contrast to what was previously observed within other guanaco populations. Besides stressing the behavioral plasticity of guanacos, these results suggest an additional adaptive function of localized-defecation other than demarcating territory ownership by the territorial male. [ABSTRACT FROM AUTHOR]

Recent studies suggest that territorial defense can act as a regulating agent of herbivore density, buffering crowding effects and preventing vegetation depletion. The occurrence of territorial families and non-territorial male groups, both major social units in the social organization of guanacos, offers the unusual opportunity to test predictions about the role of territorial defense in buffering grazing impact. Under the hypothesis that forage use by guanacos in family groups would be less intense than that of male groups which lack territorial defense, we predicted that plant cover will be higher in areas used exclusively by family groups compared to that in areas used by male groups. The vegetation and the guanaco population at San Pablo reserve were being monitored for eight years showing that grass foliar and basal cover were reduced when non-territorial groups started using the monitored area, which was previously used exclusively by family groups. On a broader scale comparison, grass and basal cover were higher in areas used by territorial animals than in those used by non-territorial ones. The approximate area used intensively by the non-territorial groups represents less than 18% of the surveyed area, whereas most of the reserve is exposed to less intense use by the territorial family groups. Thus, temporal and spatial comparisons support the idea that the resource-defense system lowers the disturbance rate over vegetation resources by guanaco populations when compared with other ungulates lacking territorial behavior. [ABSTRACT FROM AUTHOR]

Let be a commutative ring, a multivariate polynomial, and a finite subgroup of the group of units of satisfying a certain constraint, which always holds if is a field. Then, we evaluate , where the summation is taken over all pairwise distinct . In particular, let be a power of an odd prime, a positive integer coprime with , and integers such that divides and does not divide for all non-empty proper subsets ; then where the summation is taken over all pairwise distinct th residues modulo coprime with . [ABSTRACT FROM AUTHOR]

Although ecologists and managers have been increasingly preoccupied with the crowding consequences of overabundant herbivores, the potential role of territorial behavior as a self-regulatory agent has seldom been considered. The crowding mechanism underlies most regulation models in ungulate demography and relies on the assumption of an equal share of available supplies among individuals. In contrast, in territorial systems dominant individuals monopolize resources, predicting deviations from the expected demographic outcomes under the crowding approach. We used empirical data on a protected guanaco (Lama guanicoe) population to test competing hypotheses about crowding and territorial defense as the mechanism driving density regulation in a resource-defense polygyny ungulate. We assessed density dependence on recruitment at different spatial scales and density effects on preferred forage availability. The guanaco density inside the reserve increased rapidly and then stabilized during the last third of the study period. The absence of density effects on recruitment questions the existence of crowding mechanisms. Guanaco numbers stabilized below the environmental carrying capacity predicted by an equal share of available forage, supporting territorial defense as the mechanism shaping population density in the area. Variability in forage cover was independent from changes in population density, rejecting crowding effects on food supplies. These results are consistent with the hypothesis of a self-regulatory mechanism derived from resource defense that may prevent overgrazing. Our findings suggest that other factors in addition to food availability may determine the demographic carrying capacity under resource defense systems, stressing the importance of accounting for behavioral traits when addressing management issues. [ABSTRACT FROM AUTHOR]

During the ongoing coronavirus disease 2019 (COVID-19) pandemic, a number of autoimmune diseases have been found to be associated with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, with thrombocytopenia being the most common. The present study describes the case of a female patient who tested positive for SARS-CoV-2 infection from samples from two nasopharyngeal swabs examined using RT-PCR; she was admitted to hospital for severe anaemia. The woman also tested positive to direct antiglobulin test (DAT). In addition, the literature was reviewed for cases of anaemia concomitant to COVID-19 and only cases of autoimmune haemolytic anaemia (AIHA) with positive DAT were considered. A total of 38 cases of AIHA concomitant to COVID-19 were identified. In the cases reported in the literature, both warm AIHA and cold agglutinin disease were observed, with a marked prevalence of CAD. The majority of the cases identified in the literature, including the patient described herein, have had a full recovery from both COVID-19 and AIHA; however, as some of the patients visited the hospital for observation when their condition was already at an advanced and severe stage, effective therapy could not be administered and they consequently succumbed. On the whole, as autoimmune anaemia may be a consequence of SARS-CoV-2 infection, it should perhaps be considered among the haematological autoimmune disorders secondary to COVID-19, along with thrombocytopenia. [ABSTRACT FROM AUTHOR]

Listeria (L.) monocytogenes is a gram-positive, non-sporulating, facultatively anaerobic bacillus transmitted to humans through ingestion of contaminated foods. Listeriosis represents the third most common cause of death from foodborne illness, with a mortality rate of 20-30%, especially for patients affected by an invasive disease, which typically affects immunocompromised patients, pregnant women, the elderly, and neonates. It causes several clinical syndromes, of which meningitis, meningoencephalitis, and sepsis are the most challenging to deal with. Here, five cases of L. monocytogenes meningitis/meningoencephalitis affecting two previously healthy immunocompetent and three immunocompromised adult patients treated with ampicillin plus gentamicin are reported. In addition, all the patients described in this report received a low dose of intravenous dexamethasone; four of them made a full recovery. Additionally, a literature search was performed to better explain the appropriate clinical and therapeutic management approaches for these patients, highlighting the value of dexamethasone administration as part of the therapy. [ABSTRACT FROM AUTHOR]

Laryngeal leishmaniasis represents an infrequent manifestation of mucosal leishmaniasis, and even rarer is the coexistence of mucosal and visceral relapse. The present study describes the case of the simultaneous occurrence of relapsing mucosal and visceral leishmaniasis in a patient infected with human immunodeficiency virus (HIV) who was under secondary prophylaxis with liposomal amphotericin B. The clinical manifestations, diagnostic approaches employed and the treatment regimen implemented are described herein. Furthermore, the present study discusses the implications of the co-infection between leishmaniasis and HIV on the host immune response and the management strategies employed for relapsing forms. Emphasizing the necessity for the prompt initiation of targeted treatment to enhance clinical outcomes, the present study underscores the critical importance of maintaining a heightened level of suspicion for laryngeal leishmaniasis relapse in individuals with HIV exhibiting persistent laryngeal symptoms. [ABSTRACT FROM AUTHOR]

Molecular compounds with photoswitchable magnetic properties have been intensively investigated over the last decades due to their prospective applications in nanoelectronics, sensing and magnetic data storage. The family of copper-nitroxide-based molecular magnets represents a new promising type of photoswitchable compounds. We report the first study of these appealing systems using femtosecond optical spectroscopy. We unveil the mechanism of ultrafast (<50 fs) spin state photoswitching and establish its principal differences compared to other photoswitchable magnets. On this basis, we propose potential advantages of copper-nitroxide-based molecular magnets for the future design of ultrafast magnetic materials. [ABSTRACT FROM AUTHOR]

Molecular compounds with photoswitchable magnetic properties have been intensively investigated over the last decades due to their prospective applications in nanoelectronics, sensing and magnetic data storage. The family of copper-nitroxide-based molecular magnets represents a new promising type of photoswitchable compounds. We report the first study of these appealing systems using femtosecond optical spectroscopy. We unveil the mechanism of ultrafast (<50 fs) spin state photoswitching and establish its principal differences compared to other photoswitchable magnets. On this basis, we propose potential advantages of copper-nitroxide-based molecular magnets for the future design of ultrafast magnetic materials. [ABSTRACT FROM AUTHOR]

Ungulates living in predator-free reserves offer the opportunity to study the influence of food limitation on population dynamics without the potentially confounding effects of top-down regulation or livestock competition. We assessed the influence of relative forage availability and population density on guanaco recruitment in two predator-free reserves in eastern Patagonia, with contrasting scenarios of population density. We also explored the relative contribution of the observed recruitment to population growth using a deterministic linear model to test the assumption that the studied populations were closed units. The observed densities increased twice as fast as our theoretical populations, indicating that marked immigration has taken place during the recovery phase experienced by both populations, thus we rejected the closed-population assumption. Regarding the factors driving variation in recruitment, in the low- to medium-density setting, we found a positive linear relationship between recruitment and surrogates of annual primary production, whereas no density dependence was detected. In contrast, in the high-density scenario, both annual primary production and population density showed marked effects, indicating a positive relationship between recruitment and per capita food availability above a food-limitation threshold. Our results support the idea that environmental carrying capacity fluctuates in response to climatic variation, and that these fluctuations have relevant consequences for herbivore dynamics, such as amplifying density dependence in drier years. We conclude that including the coupling between environmental variability in resources and density dependence is crucial to model ungulate population dynamics; to overlook temporal changes in carrying capacity may even mask density dependence as well as other important processes. [ABSTRACT FROM AUTHOR]

Der LIESST-Effekt ('light-induced excited spin state trapping') in Eisen(II)-Spinübergangsverbindungen, das heißt, die lichtinduzierte Population des High-spin-Zustands ( S=2) unterhalb der thermischen Übergangstemperatur, wurde vor 30 Jahren entdeckt. Für die Einstrahlung in Metall-Ligand-Charge-Transfer(MLCT)-Banden der Low-spin-Spezies ( S=0) geht die anerkannte Relaxationskaskade in etwa 150 fs vom ursprünglich angeregten 1MLCT-Zustand über den 3MLCT-Zustand direkt in den High-spin-Zustand, wobei die tiefenergetischen Ligandenfeld(LF)-Zustände umgangen werden. Die Beobachtung von LIESST und reverse-LIESST mittels Einstrahlung direkt in die LF-Banden in Systemen mit nur hochenergetischen MLCT-Zuständen zeigt, dass diese dennoch eine Rolle spielen. Hier identifizieren wir den ersten angeregten S=1-LF-Zustand als Zwischenzustand mit einer Lebensdauer von 39 ps in der Kaskade von reverse-LIESST, die auf die Anregung in den spinerlaubten LF-Übergang der high-spin Spezies im NIR folgt. [ABSTRACT FROM AUTHOR]

Light-induced excited spin-state trapping (LIESST) in iron(II) spin-crossover compounds, that is, the light-induced population of the high-spin ( S=2) state below the thermal transition temperature, was discovered thirty years ago. For irradiation into metal-ligand charge transfer (MLCT) bands of the low-spin ( S=0) species the acknowledged sequence takes the system from the initially excited MLCT to the high-spin state via the 3MLCT state within ca. 150 fs, thereby bypassing low-lying ligand-field (LF) states. Nevertheless, these play a role, as borne out by the observation of LIESST and reverse-LIESST on irradiation directly into the LF bands for systems with only high-energy MLCT states. Herein we elucidate the ultrafast reverse-LIESST pathway by identifying the lowest energy S=1 LF state as an intermediate state with a lifetime of 39 ps for the light-induced high-spin to low-spin conversion on irradiation into the spin-allowed LF transition of the high-spin species in the NIR. [ABSTRACT FROM AUTHOR]

For large herbivores, predation-risk, habitat structure and population density are often reported as major determinants of group size variation within and between species. However, whether the underlying causes of these relationships imply an ecological adaptation or are the result of a purely mechanistic process in which fusion and fragmentation events only depend on the rate of group meeting, is still under debate. The aim of this study was to model guanaco family and bachelor group sizes in contrasting ecological settings in order to test hypotheses regarding the adaptive significance of group-size variation. We surveyed guanaco group sizes within three wildlife reserves located in eastern Patagonia where guanacos occupy a mosaic of grasslands and shrublands. Two of these reserves have been free from predators for decades while in the third, pumas often prey on guanacos. All locations have experienced important changes in guanaco abundance throughout the study offering the opportunity to test for density effects. We found that bachelor group size increased with increasing density, as expected by the mechanistic approach, but was independent of habitat structure or predation risk. In contrast, the smaller and territorial family groups were larger in the predator-exposed than in the predator-free locations, and were larger in open grasslands than in shrublands. However, the influence of population density on these social units was very weak. Therefore, family group data supported the adaptive significance of group-size variation but did not support the mechanistic idea. Yet, the magnitude of the effects was small and between-population variation in family group size after controlling for habitat and predation was negligible, suggesting that plasticity of these social units is considerably low. Our results showed that different social units might respond differentially to local ecological conditions, supporting two contrasting hypotheses in a single species, and highlight the importance of taking into account the proximate interests and constraints to which group members may be exposed to when deriving predictions about group-size variation. [ABSTRACT FROM AUTHOR]

Abstract: We report here on the ultrafast photo-switching dynamics of a Fe(II) molecular material [Fe(PM-AzA)2(NCS)2]. It undergoes a thermal spin-crossover which can be detected by magnetic measurements or by optical reflectivity. We use here femtosecond optical reflectivity to study the ultrafast photo-switching dynamics. Our results indicate that the HS state is reached from the LS state within less than 100fs, through an intermediate MLCT state. This ultrafast relaxation from the electronic excited state towards the structurally relaxed HS state is followed by a vibrational cooling of the hot HS molecules within ≈1ps timescale. [Copyright &y& Elsevier]

Sheep rearing is the main productive activity in Patagonian rangelands, where guanacos are the only native ungulate. Ranchers perceive a decrease in range carrying capacity as guanaco numbers increase, therefore guanaco conservation within private lands becomes a considerable challenge. This issue is particularly evident in the World Natural Heritage Península Valdés (PV), where there is a need to harmonize livestock production and biodiversity conservation. While sheep rearing prevails as the primary land use in the area, some ecotourism initiatives have been implemented to complement livestock production. In order to study how land use affected guanaco distribution, we characterized PV's ranches in terms of land subdivision, primary productivity, stocking-rate and management type, and assess how these variables affected guanaco encounter rates. Smaller ranches were composed of smaller paddocks (mean size 4.8 km2), which showed higher values of the remote-sensing derived Enhance Vegetation Index (EVI) (mean 0.14) and held higher sheep densities (mean 108.0 sheep/km2), while larger management units (mean size 23.8 km2), showed lower EVI values (mean 0.12) and lower stocking-rates (mean 36.7 sheep/km2). This pattern suggests that primary productivity has been a decisive factor to determine the minimal paddock size set by ranchers in PV, apparently precluding excessive land-subdivision in less productive areas. Guanaco encounter rate, expressed as number of guanacos per travelled kilometre, was inversely related to EVI and stocking-rate. However, land subdivision was the better predictor of guanaco encounter-rate within only sheep ranches, finding more guanacos per kilometre as paddock size increased. In contrast, in ranches where ecotourism was implemented as a complementary activity, guanaco encounter-rates were greater, regardless of paddock size. Our results suggest that the implementation of an additional activity by which landowners derive benefits from wildlife has prompted a beneficial outcome for guanacos, presumably through a decrease in harassment intensity. Finally, we propose possible mechanisms by which land subdivision may affect guanaco distribution and potential alternatives for the inclusion of wildlife conservation in a context of extensive livestock production. [ABSTRACT FROM AUTHOR]