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Background/Aim. Plasma containing a high titer of anti-SARS-CoV-2 antibodies, donated from individuals who recovered from COVID-19, has the potential to be used as initial therapy for patients who have been infected (passive immunization). It is a challenge to find suitable donors. The aim of the study was to successively monitor antibody titer in donations and to investigate the correlation between antibody titer and the severity of the clinical manifestations. Methods. The retrospective study was conducted from May 1 to October 31, 2020, at the Blood Transfusion Institute of Vojvodina. Donors had to meet certain criteria for inclusion in the study: proven SARS-CoV-2 infection, detected SARS-CoV-2 antibodies in the serum/plasma, fulfillment of general criteria for performing plasmapheresis, and adequate laboratory findings. Results. During the study, 651 apheresis plasma units were collected and divided into two equal doses. Plasma was donated by 311 COVID- 19 convalescents, including 208 (66.9%) men and 103 (33.1%) women. There were 15 (4.8%) plasma donors with asymptomatic infection, 235 (75. 6%) with a mild form of illness, 45 (14.5%) with a moderate form of illness, 16 (5.1%) with a severe form of illness, and none with a critical form of illness. Anti-SARS-CoV-2 IgG antibodies were present in the plasma of donors for more than 6 months after the disease. Plasma donors with a more severe clinical manifestation of COVID-19 had stable antibody levels for a longer period. However, the Pearson correlation of clinical severity and antibody titer did not confirm a statistically significant correlation between the variables. Conclusion. Anti-SARS-CoV-2 antibodies were present in the sample of recovered patients, plasma donors, for more than 6 months after the disease. Even though no statistically significant correlation was found between the anti-SARS-CoV-2 anti-body titer and the clinical severity of COVID-19, in patients with a more severe clinical manifestations of the disease, stable antibody levels were maintained for a longer period.

Background/Aim. Pregnancy-induced red blood cell (RBC) alloimmunization is important not only because of the possible negative effects on subsequent pregnancy outcomes in case the fetus carries the antigen but also because of the optimal trans-fusion management in cases of obstetric hemorrhage. Timely detection of RBC antibodies is part of testing, prevention, and treatment strategy, aimed at achieving better outcomes for alloimmunized mothers with an affected fetus. The aim of the study was to determine the frequency and specificity of alloantibodies among pregnant women from the South Bačka District, Serbia, with special attention to the incidence of anti-D alloantibodies. Methods. A retrospective study was conducted in the Blood Transfusion Institute of Vojvodina and covered the period from January 1, 2010, to December 31, 2019. Screening and antibody identification were performed by an indirect antiglobulin test in gel-microcards (ID-Card Liss/Coombs) with two test RBC (ID-DiaCell I-II screening cells, Bio-Rad, Cressier, Switzerland) on an automated system (IH-500, Bio-Rad). Results. Among 25,694 tested pregnant women, 1.38% were actively immunized, while 1.12% of women acquired antibodies in the current pregnancy. Among 3,622 (14.09%) RhD-negative women, 1.77% produced anti-D antibodies during the ongoing pregnancy. Distribution of anti-body specificity was: anti-D 23.34%, anti-M 11.85%, anti-E 9.41%, anti-K 9.41%, anti-C 5.92%, anti-Fyb 5.92%, anti-c 3.13%, anti-S 3.13%, anti-Lea 3.13%, anti-Leb 3.13%, anti-Cw 1.75%, anti-Jka 1.40%, anti-P 1.05%, anti-Lub 0.70%, anti-Fya 0.35%, autoantibody of undetermined specificity 0.70%, and irregular antibodies of undetermined specificity 15.68%. Conclusion. Immunoglobulin prophylaxis has led to a significant reduction in the frequency of D-alloimmunization among pregnant women in the South Bačka District over the last ten years. However, the incidence of anti-D antibodies is still significantly higher than in published data for developed countries. We also identified the other, less commonly present, clinically significant antibodies. There is a need to introduce uniform recommendations for immunohematological testing in pregnancy on the territory of the Republic of Serbia in accordance with modern requirements.

Background/Aim. Plateletpheresis (PLTP) is a medical procedure used for collecting donor platelets with multiple benefits for patients who will receive apheresis platelets. The procedure takes one hour and is well tolerated by donors. Nevertheless, adverse events (AEs) may occur during and after the PLTP procedure. The aim of the study was to determine the incidence and type of AEs associated with PLTP in donors. Methods. A retrospective analysis of AEs associated with donor PLTP was conducted at the Blood Transfusion Institute of Vojvodina from January 1, 2010, to December 31, 2019. Results. Out of 2,073 plate-let donors, 94.84% were multiple blood donors, predominantly male (98.55%). AEs were identified during 180 (8.68%) platelet donations with no statistical significance in occurrence in the first time donors (10.28%) and repeat donors (8.59%). Mild local reactions related to venous access (42.22%) were the most common AEs. Generalized symptoms were exhibited in 16.67% of donors, 26.11% exhibited symptoms related to apheresis (citrate reactions), and 15% exhibited those related to other complications. It was found that 95.55% of AEs occurred during PLTP and only 4.45% after it. Conclusion. Donor PLTP is a generally safe procedure, well tolerated by donors. Understanding risk factors for a possible occurrence of AEs provides support for adopting measures to prevent them.

Complex network analyses of many physical, biological and social phenomena show remarkable structural regularities [1]-[3], yet, their application in studying human past interaction remains underdeveloped. Here, we present an innovative method for identifying community structures in the archaeological record that allows for independent evaluation of the copper using societies in the Balkans, from c. 6200 to c. 3200 BC. We achieve this by exploring modularity of networked systems of these societies across an estimated 3000 years. We employ chemical data of copper-based objects from 79 archaeological sites as the independent variable for detecting most densely interconnected sets of nodes with a modularity maximization method [4]. Our results reveal three dominant modular structures across the entire period, which exhibit strong spatial and temporal significance. We interpret patterns of copper supply among prehistoric societies as reflective of social relations, which emerge as equally important as physical proximity. Although designed on a variable isolated from any archaeological and spatiotemporal information, our method provides archaeologically and spatiotemporally meaningful results. It produces models of human interaction and cooperation that can be evaluated independently of established archaeological systematics, and can find wide application on any quantitative data from archaeological and historical record. [ABSTRACT FROM AUTHOR]

All activities, including education, are underpinned by values. Since its beginnings, education has promoted various values, and at the same time was itself perceived as a value, which is a prerequisite for performing its social function. The crisis of contemporary civilization makes it essentially important for school as an educational institution, and for teachers as its key actors, to demonstrate unequivocally by personal example that they perceive education as a value, not only declaratively but also through their professional activities. The current study aimed to explore teachers' perceptions of education as a value in school culture, specifically, their perceptions of education as a mechanism for promoting employees within an organization and their perceptions of measures and procedures in the organization aimed at facilitating employees' education. Our findings suggest that education is not regarded as an organizational value within the culture of the schools included in our study

In order to prevent hypovolemic shock and its consequences early diagnosis and prompt treating of the patient is vital, as well as the urgent provision of blood. The most important aspects of effective blood supply are: 1) efficient communication (emergency physicians, surgeons, anesthesiologists, specialist in transfusion medicine, haematologist, support services); 2) documenting/investigating (reports of adverse reactions and errors or incidents associated with massive blood transfusions, evidence of harm; 3) implementation of national guidelines and local protocols for clinic and laboratory management of major haemorrhage; 4) pretransfusion testing (ABO group and RhD typing of patients red cells, full serological blood cross-matching which includes anti-human globulin phase AHG). In emergency situations the following can also be applied: a) O RhD-negative uncrossmatched blood; b) ABO and Rhesus-compatible uncrossmatched blood; c) ABO and Rhesus-compatible crossmatched blood (without AHG).

Introduction. The concept of blood safety includes the entire transfusion chain starting with the collection of blood from the blood donor, and ending with blood transfusion to the patient. The concept involves quality management system as the systematic monitoring of adverse reactions and incidents regarding the blood donor or patient. Monitoring of near-miss errors show the critical points in the working process and increase transfusion safety. Objective. The aim of the study was to present the analysis results of adverse and unexpected events in transfusion practice with a potential risk to the health of blood donors and patients. Methods. One-year retrospective study was based on the collection, analysis and interpretation of written reports on medical errors in the Blood Transfusion Institute of Vojvodina. Results. Errors were distributed according to the type, frequency and part of the working process where they occurred. Possible causes and corrective actions were described for each error. The study showed that there were not errors with potential health consequences for the blood donor/patient. Errors with potentially damaging consequences for patients were detected throughout the entire transfusion chain. Most of the errors were identified in the preanalytical phase. The human factor was responsible for the largest number of errors. Conclusion. Error reporting system has an important role in the error management and the reduction of transfusion-related risk of adverse events and incidents. The ongoing analysis reveals the strengths and weaknesses of the entire process and indicates the necessary changes. Errors in transfusion medicine can be avoided in a large percentage and prevention is costeffective, systematic and applicable.

Excessive blood loss can lead to hemorrhagic shock which is life threatening for the patient so timely diagnosis and intervention can be crucial for its survival. Rapid provision of blood and blood products is an integral part of the entire process. The use of blood products must be rational and efficient which involves the use of appropriate blood components at the right time. The conditions are: 1) Determination the degree of urgency (according to the protocol for the care of bleeding patients, with fast and efficient communication between clinic staff and transfusion service, the provision of a patient's blood sample and its transport to the transfusion service); 2) Selection of blood components depending on the clinical condition of the patient and his hemodynamic parameters: a) erythrocite, b) fresh frozen plasma, c) cryoprecipitate, d) platelets; 3) Determining the scope of pretransfusion testing: ABO/ RhD blood grouping, anti-human globulin cross match (AHG-XM), the immediate spin cross match without AHG phase, in special situations without blood grouping and cross matching; 4) Reporting and investigation of all posttransfusion reactions (immune/ non-immune, early/ delayed). Patients with massive bleeding require emergency treatment, good communication and cooperation between several physicians of different specialties, as well as fast and efficient transfusion of appropriate blood components.

Erectile dysfunction (ED) is a disorder, which basically can have organic nature, psychological or mixed. ED is not a rarity, and data on its prevalence vary, depending on the areas in which the survey was conducted, followed by a period of research and the definition of the disorder. Most of the men associate ED problem with using drugs, especially cardiac. Even though there is some truth in it, mainly the real causes of ED are not well known even to professionals. Contemporary studies of risk factors for cardiovascular disease, particularly coronary heart disease, have shown the clear link between erectile dysfunction and coronary heart disease, wherein ED first manifests. While, ED precedes the onset of symptoms of coronary heart disease and show to the patient and the physician a clear signal of the direction for conducting diagnostic tests and further treatment in the interest of the health of patients. Endocrine, and neurological disorders, as well as bad habits in addition to the cardiac and kidney disease, lead to ED. It is known also, that the use of cardiac medicines may contribute to ED occurrence. Better knowledge of adverse reactions to medicines, a better understanding of the nature of the disease and the implementation of necessary diagnostic procedures, with a good choice of medication, contribute to solving problems related to ED. If all mentioned do not help, there is the possibility of using new drugs to correct ED.

Background/Aim. One of the possible complications after implantation of a cement hip-joint endoprosthesis is fracture in the endoprosthesis body. Fractures arise from overload or material fatigue of which an implant is made. The purpose of this research was to define the intensity of maximum stress and the positions of a critical cross-section in the endoprosthesis body. Methods. Unilaterally changing forces which act on the hip joint during walking as well as the loads result in flexible deformations of the endoprosthesis body. Biomechanical analysis of the forces acting on the hip joint determine their direction and intensity, whereas on the basis of Gruen’s classification of the endoprosthesis body loosening the level of fixation is established. The bodies of cement hip joint endoprosthesis are made of cobalt-chromiummolybdenum (CoCrMo) alloy, suitable for vacuum casting, are submitted to the analysis. Analysis of the critical stress in the endoprosthesis body was performed on the endoprosthesis body by means of the finite element method. The experimental verification of the obtained results was carried out on the physical prototype under laboratory conditions. Results. Computer analysis, by means of the finite element method, determined the stress state by calculation of the maximum Von Mises stress and critical cross-sections for different angles of the resultant force action. The results obtained by the computer and experimental method correlate and are comparable to the results of similar analyses conducted on various endoprosthesis types. Conclusion. The analyses described in the paper make the basis for improving the process designing of hip joint endoprostheses and their customization to each individual patient (custom made). [Projekat Ministarstva nauke Republike Srbije, br. TR 35025]

It is the characteristic of the entire region of the former Yugoslavia that veterans of regional wars 1991-1999 are marginalized social group. Besides negative consequences for veterans, the marginalization strongly affects the whole communities, as well as very sensitive regional post conflict relations. Still, negative consequences that veterans suffer nowadays can be transformed into precious, positive potential for building of a good and healthy post-conflict societies and good neighborhood relationships as well. This paper is focused on the position of war veterans from Serbia, which recently became the subject of public debate on the occasion of the publication of the book "Oh, where have you been, my blue-eyed son?".

In this paper Serbian press’ approach toward refugees as a topic, for period of last fifteen years is analyzed. The analyses is built up on huge database of all articles about refugees published in progovernment and independent daily and weekly Serbian press, in mentioned period. Results of this research are crushing: differences of approaches in pro-government and independent press are minor; both press profiles, despite of what was expected, were shown equal lack of understanding toward the topic, contributing to social marginalization of refugees. Professional ethical codex have been remarkably violated all the time. These findings are part of a forthcoming book "Political framing of refugees: 1990. – 2005.".

This research explores the association between ABO blood groups and susceptibility to SARS-CoV-2 infection, analyzing Convalescent COVID-19 plasma (CCP) donors ( n = 500) and healthy whole blood donors (BDs) ( n = 9678) during the pandemic (1 May 2020 to 30 April 2021). A comparison is made with pre-pandemic BDs ( n = 11,892) from 1 May 2018 to 30 April 2019. Significant differences in blood group distribution are observed, with blood group A individuals being three times more likely to be CCP donors. Conversely, blood groups B, O, and AB are less associated with CCP donation. Notably, blood group O is more prevalent among regular BDs, suggesting potential resistance to SARS-CoV-2 infection. This study underscores variations in blood group distribution during the pandemic compared to pre-pandemic periods. The findings support previous research indicating a link between blood group antigens and viral susceptibility, including SARS-CoV-2. Understanding these associations has implications for public health strategies, with potential for predicting COVID-19 outcomes and transmission patterns. Further research is crucial to explore molecular and immunological mechanisms, providing valuable insights for targeted preventive strategies and personalized healthcare in managing the impact of COVID-19.

Many patients require administering one or more blood components during hospitalisation in the Intensive Care Unit (ICU). Therefore, nurses' knowledge of who is responsible for immediately administering blood transfusions, monitoring patients, and identifying and managing transfusion reactions is crucial. This cross-sectional descriptive-analytical study aimed to assess the knowledge of ICU nurses in tertiary healthcare institutions about blood transfusion procedures. The questionnaire about the transfusion procedure was designed and reviewed by experts. The questionnaire consisted of 29 items divided into three domains. The scores on the knowledge test ranged from 10 to 27. Generally, 57.7% of nurses had moderate, 23.4% low, and 18.9% high levels of knowledge about the transfusion procedure. Most nurses answered correctly about refreezing fresh frozen plasma, verifying the transfusion product, and identifying the patient. Of the nurses, 91.0% would recognise mild allergic reactions, and 98.2% knew about the supervision of sedated patients. Nurses showed poor knowledge of the length of usage of the same transfusion system for red blood cells, labelling, and transfusion administration in febrile patients. Nurses with higher education and longer working experience had significantly better outcomes ( p = 0.000) on the knowledge test. Continuous education of ICU nurses on safe transfusion usage is recommended.

Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are important tick-borne diseases in Europe. This study aimed to investigate the seroreactivity against Borrelia burgdorferi and TBE virus (TBEV) in tick-infested individuals in North Macedonia and Serbia. Serum samples were collected from tick-infested individuals and from healthy individuals in the same regions. Samples were tested for anti- Borrelia IgG reactivity and TBEV-neutralizing antibodies. Results showed higher seroreactivity against Borrelia antigens in patients and healthy donors from Novi Sad compared to those from the Skopje region. However, there was no statistically significant difference between tick-infested patients and healthy donors within each region. No TBEV-neutralizing antibodies were detected in participants from Novi Sad or in the control groups, except for one person from North Macedonia who had a moderate TBEV-neutralizing reaction. The study highlights the need for improved surveillance and diagnostic capabilities for LB and TBE in these regions. It also suggests the potential existence of TBEV foci in North Macedonia. The findings provide a complementary understanding of the LB and TBE epidemiology in the studied regions; however, further research is needed to investigate the presence and distribution of Borrelia spp. and TBEV in ticks to assess the significance of detected seroreactivity.

Objective: Cubital tunnel syndrome (CuTS) results from compression of the ulnar nerve at the elbow, resulting in pain, weakness, and numbness of the hand and forearm. This work describes the Quality of Life (QoL) and satisfaction after CuTS surgery and identifies the factors associated with those outcomes., Methods: This cross-sectional study included patients surgically treated for CuTS from January 2011 to September 2021 at the Neurosurgery Clinic of the Clinic Center in Serbia. The questionnaires applied were the Short Form 36 (SF-36), EuroQol instrument (EQ-5D-5 L), Bishop's score and Patient-Rated Ulnar Nerve Evaluation (PRUNE)., Results: Sixty-two patients met the inclusion criteria. Bishop's score: The median score was 10 (7.75-11), 54.8% of the cases presented excellent results. PRUNE: The median score for symptoms was 19 (6-38.5); for functional, was 14 (0.75-38); and the total was 18.25 (5.87-34.12). SF-36: The subscale with the best result was social functioning (84.68 ± 22.79). The scale with the worst value was emotional well-being (49.35 ± 7.87). EQ-5D-5L: Over 50% patients did not present problems with mobility, self-care, activity, and anxiety. The average EQ-VAS was 72.77 ± 18.70; and 0.72 ± 0.21 of the EQ-index, revealing a good QoL. Models for QoL and satisfaction: Ten models showed statistical significance. The variables with major involvement were body mass index and time evolution of the symptoms., Conclusion: Surgical decompression has proved to diminish the symptoms, improving QoL and satisfaction. Many fixed and changeable factors can affect the satisfaction levels after surgery.

A 48-year-old female was admitted to the authors' department due to hand weakness as a consequence of C8, T1 root injury. Eight months earlier, the patient had been treated by a pulmonary surgeon due to an expansive lesion near the apex of the right lung, which resulted in right lower brachial plexus palsy. Postoperative pathohistological findings indicated that the lesion was nerve schwannoma. The diagnostic process included physical examination, electromyoneurography, and MRI. A distal nerve transfer (pronator teres-anterior interosseus nerve [PT-AIN], supinator-posterior interosseus nerve [SUP-PIN]) was performed in order to restore hand function. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID22110., Competing Interests: Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this publication.The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this publication., (© 2023, The Authors.)

Introduction: The phrase "think globally, act locally", which has often been used to refer to conservation of the environment, highlights the importance of maintaining a holistic perspective and stipulates that each individual has a role to play in their community and larger world. Although peripheral nerve surgery has been largely unemphasized in global neurosurgical efforts, a wide disparity in peripheral nerve surgery is presumed to exist between high-income and low- and middle-income countries. Serbia is an upper middle-income country with a long history of peripheral nerve surgery., Research Question: How can understanding the development of peripheral nerve surgery in Serbia advance global education and improve peripheral nerve surgery worldwide?, Material and Methods: An anecdotal and narrative review of recent advances in peripheral nerve surgery in Serbia was conducted. The World Federation of Neurosurgical Society (WFNS) Peripheral Nerve Surgery Committee discussions on improving peripheral nerve surgery education were summarized., Results: In this manuscript, we describe the application of "think globally, act locally" to peripheral nerve surgery by providing an account of the development of peripheral nerve surgery in Serbia. Then, we report measures taken by the WFNS Peripheral Nerve Surgery Committee to improve education on peripheral nerve surgery in LMICs., Discussion and Conclusion: Viewing the development of peripheral nerve surgery in Serbia through the lens of "think globally, act locally" may guide the development of peripheral nerve surgery in LMICs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Introduction: Radial nerve lesions present a clinical entity that may lead to disability, psychological distress, and job loss, and thus requires great attention. Knowledge of the etiology and exact mechanism of the nerve impairment is of great importance for appropriate management of these patients, and there are only a few papers that focused on these features in patients with surgically treated radial nerve lesions. The lack of studies presenting the etiology and injury mechanisms of surgically treated radial nerve lesions may be due to a relatively small number of specialized referral centers, dispersion to low-flow centers, and a greater focus on the surgical treatment outcomes., Aim: The aim of this study was to describe the etiological and epidemiological characteristics of patients with surgically treated radial nerve lesions of various origins., Methods: This retrospective study evaluated 147 consecutive patients with radial nerve lesion, treated in the department during the last 20 years, from January 1, 2001, until December 31, 2020., Results: The majority of patients belonged to the working population, and 70.1% of them were male. Most commonly, the etiology of nerve lesion was trauma (63.3%) or iatrogenic injury (28.6%), while the less common origin was idiopathic (4.1%) or neoplastic (4.1%). The most frequent location of the lesion was in the upper arm, followed by the elbow and forearm. Fracture-related contusion was the most common mechanism (29.9%), followed by postoperative fibrosis (17.7%), lacerations (17.7%), and compression (15.6%)., Conclusion: Based on the fact that traumatic or iatrogenic injuries constitute the majority of cases, with their relevant mechanisms and upper arm predomination, it is crucial to raise awareness and understanding of the radial nerve injuries among orthopedic surgeons to decrease the numbers of these patients and properly preserve or treat them within the initial surgery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2022 Rasulić, Djuraskovic, Lakićević, Lepić, Savić, Grujić, Mićić, Radojevic, Cordoba Mosqueda, Visani, Puzovic, Kovačević, Vitošević, Mandic-Rajcevic and Knezevic.)

The reduction in the risk of transfusion-transmissible infections (including HIV infection) is an essential part of transfusion patient care. Here, we report the first incident of HIV transmission via transfusion in north Serbia due to blood donor dishonesty, and the failure of the laboratory screen tests to detect the presence of HIV particles in his blood. Infected blood products were distributed to two recipients, and HIV infection was confirmed in one. This incident finally led to the implementation of Nucleic Acid Amplification Technology as mandatory testing of blood donors for HIV infection in Serbia and raised many questions related to the responsibility and ethics of all the participants in the blood transfusion supply chain. There is a need for the implementation of modern and non-discriminative laws in Serbia in order to reduce transfusion-transmissible infections. In addition, transfusion institutes in Serbia need to be obliged to pursue the constant upgrade of their diagnostic capacities in order to prevent similar incidents and to provide the best possible care for blood donation recipients.

Home assistant chat-bots, self-driving cars, drones or automated negotiation systems are some of the several examples of autonomous (artificial) agents that have pervaded our society. These agents enable the automation of multiple tasks, saving time and (human) effort. However, their presence in social settings raises the need for a better understanding of their effect on social interactions and how they may be used to enhance cooperation towards the public good, instead of hindering it. To this end, we present an experimental study of human delegation to autonomous agents and hybrid human-agent interactions centered on a non-linear public goods dilemma with uncertain returns in which participants face a collective risk. Our aim is to understand experimentally whether the presence of autonomous agents has a positive or negative impact on social behaviour, equality and cooperation in such a dilemma. Our results show that cooperation and group success increases when participants delegate their actions to an artificial agent that plays on their behalf. Yet, this positive effect is less pronounced when humans interact in hybrid human-agent groups, where we mostly observe that humans in successful hybrid groups make higher contributions earlier in the game. Also, we show that participants wrongly believe that artificial agents will contribute less to the collective effort. In general, our results suggest that delegation to autonomous agents has the potential to work as commitment devices, which prevent both the temptation to deviate to an alternate (less collectively good) course of action, as well as limiting responses based on betrayal aversion., (© 2022. The Author(s).)

While many theoretical studies have revealed the strategies that could lead to and maintain cooperation in the Iterated Prisoner's dilemma, less is known about what human participants actually do in this game and how strategies change when being confronted with anonymous partners in each round. Previous attempts used short experiments, made different assumptions of possible strategies, and led to very different conclusions. We present here two long treatments that differ in the partner matching strategy used, i.e. fixed or shuffled partners. Here we use unsupervised methods to cluster the players based on their actions and then Hidden Markov Model to infer what the memory-one strategies are in each cluster. Analysis of the inferred strategies reveals that fixed partner interaction leads to behavioral self-organization. Shuffled partners generate subgroups of memory-one strategies that remain entangled, apparently blocking the self-selection process that leads to fully cooperating participants in the fixed partner treatment. Analyzing the latter in more detail shows that AllC, AllD, TFT- and WSLS-like behavior can be observed. This study also reveals that long treatments are needed as experiments with less than 25 rounds capture mostly the learning phase participants go through in these kinds of experiments., (© 2022. The Author(s).)

Passive immunotherapy with convalescent COVID-19 plasma (CCP) is used as a therapeutic procedure in many countries, including Serbia. In this study, we analyzed the association between demographic factors, COVID-19 severity and the reactivity of anti-SARS-CoV-2 antibodies (Abs) in Serbian CCP donors. Individuals ( n = 468) recovered from confirmed SARS-CoV-2 infection, and who were willing to donate their plasma for passive immunization of COVID-19 patients were enrolled in the study. Plasma samples were tested for the presence of IgG reactive to SARS-CoV-2 spike glycoprotein (S1) and nucleocapsid antigens. Individuals were characterized according to age, gender, comorbidities, COVID-19 severity, ABO blood type and RhD factor. Total of 420 candidates (420/468; 89.74%) reached the levels of anti-SARS-CoV-2 IgG that qualified them for inclusion in CCP donation program. Further statistical analysis showed that male individuals ( p = 0.034), older age groups ( p < 0.001), existence of hypertension ( p = 0.008), and severe COVID-19 ( p = 0.000) are linked with higher levels of anti-SARS-CoV-2 Abs. These findings will guide the selection of CCP donors in Serbia. Further studies need to be conducted to assess the neutralization potency and clinical efficiency of CCP collected from Serbian donors with high anti-SARS-CoV-2 IgG reactivity.

Radial nerve injuries are often associated with humeral shaft fractures. The results of treatment of these injuries, by contemporary surgical approaches, remain diverse. In this paper we presented the outcomes and analyzed the patient, clinical, and surgical procedure related characteristics and factors that may influence the outcome overall, in 77 patients treated at Clinic for Neurosurgery, Clinical Center of Serbia during a 20 years period. The nerve injuries were verified by US and EMNG. The majority of patients were treated by neurolysis or sural nerve grafting, while only few were treated by direct suture. The final recovery was evaluated by muscle strength assessment and classified using MRC. We analyzed extension of the wrist, extension of the fingers including the thumb, and abduction of the thumb. There was a significant statistical difference in MRC grade following the treatment. The total rate of useful functional recovery was achieved in 69 (89.61%) out of all studied patients, out of whom 20 (28.99%) achieved excellent recovery, 26 (37.68%) achieved good recovery and 23 (33.33%) achieved fair recovery. Only 8 (10.39%) out of all studied patients achieved poor recovery. The injured nerves, that were preserved in continuity, acquired by a low-energy trauma, and treated earlier than the 6 months were associated with better functional outcome following the surgery. In addition, there was a trend of better functional improvement with aging, keeping in mind that the old were subjected to lower energy trauma. The expectant management followed by surgery of radial nerve injury associated with humeral shaft fracture should be around 3 months, and the surgical nerve repair should not be performed later than the 6 months after injury. The energy of trauma may be a factor predicting patient's final recovery following the treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Rasulić, Djurašković, Lakićević, Lepić, Savić, Grujić, Mićić, Radojević, Puzović, Maletić and Mandić-Rajčević.)

Lyme borreliosis (LB) is the most common tick-borne disease in Serbia and other European countries. Rabies is a fatal zoonosis distributed worldwide and is caused by the rabies virus. Professionals at risk of rabies-including veterinarians, hunters, communal service workers, and forestry workers-overlap with some professions at a higher risk of exposure to tick bites and tick-borne pathogen infections. We hypothesized that individuals identified by the public health system as at risk of rabies virus infection, and consequently vaccinated against rabies virus, also share a higher likelihood of Borrelia exposure. To test our hypothesis, a case-control study was carried out during 2019 in Serbia to determine the seroprevalence of anti- Borrelia antibodies in two case groups (individuals at risk and vaccinated against rabies virus) and a control group (individuals without risk of rabies). Individuals vaccinated against rabies following either "pre-exposure protocol" (PrEP, n = 58) or "post-exposure protocol" (PEP, n = 42) were considered as rabies risk groups and healthy blood donors ( n = 30) as the control group. The results showed higher Borrelia seroprevalence in PrEP (17.2%; 10/58) and PEP (19.0%; 8/42) groups compared with the control group (6.67%; 2/30). Furthermore, odds ratio (OR) analysis showed that risk of rabies (in either the PrEP (OR = 2.91) or PEP (OR = 3.29) groups) is associated with increased odds of being seropositive to Borrelia . However, the difference in Borrelia seroprevalence between groups was not statistically significant (Chi-square (χ²) test p > 0.05). The shared odds of LB and rabies exposure found in this study suggest that, in countries where both diseases occur, the common citizen can be at risk of both diseases when in a risky habitat. These findings are important to guide physicians in targeting high-risk groups, and diagnose LB, and to guide decision-makers in targeting control and prevention measures for both infections in risk areas.

Tick-borne encephalitis (TBE), caused by the TBE virus (TBEV), is a life-threatening disease with clinical symptoms ranging from non-specific to severe inflammation of the central nervous system. Despite TBE is a notifiable disease in Serbia since 2004, there is no active TBE surveillance program for the serologic or molecular screening of TBEV infection in humans in the country. This prospective cohort study aimed to assess the TBEV exposure among tick-infested individuals in Serbia during the year 2020. A total of 113 individuals exposed to tick bites were recruited for the study and screened for anti-TBEV antibodies using a commercial indirect fluorescent antibody test (IFA) test. Blood samples from 50 healthy donors not exposed to tick bites were included as a control group. Most of the enrolled patients reported infestations with one tick, being I. ricinus the most frequent tick found in the participants. The TBEV seroprevalence was higher (13.27%, 15 total 113) in tick-infested individuals than in healthy donors (4%, 2 total 50), although the difference was not significant. Notably, male individuals exposed to tick bites showed five times higher relative risk (RR) of being TBEV-seropositive than healthy donors of the same gender (RR= 5.1, CI = 1.6-19; p = 0.007). None of the seropositive individuals developed clinical manifestations of TBE, but the first clinical-stage of Lyme borreliosis (i.e., erythema migrans) was detected in seven of them. Potential TBEV foci were identified in rural areas, mostly in proximity or within the Fruška Gora mountain. We conclude that the Serbian population is at high risk of TBEV exposure. Further epidemiological studies should focus on potential TBEV foci identified in this study. The implementation of active surveillance for TBEV might contribute to evaluating the potential negative impact of TBE in Serbia.

Objective: Brachial plexus injuries are among the most complex injuries of the peripheral nervous system and among the most devastating injuries overall. In complete lesions, functional priorities include the reinnervation of the musculocutaneous and axillary nerves for proximal functions restoration. Three major nerves - radial, median, and ulnar - and the corresponding muscles remain denervated, which results in subsequent muscle atrophy. This study was aimed at the evaluation of arm volumes in surgically treated patients with brachial plexus injuries, in correlation with the type of palsy, recovery and associated factors., Methods: The study included 36 patients with brachial plexus injuries who were surgically treated in our institution over a 15-year-long period. The evaluation of arm and arm segments volumes was carried out using water displacement testing, based on the Archimedes principle., Results: Statistically significant differences were noted between the operated arm and the healthy arm in all of the measured segments (hands, forearms and upper arms), as well as between the patients with complete and upper palsy, and in correlation with the shoulder abduction recovery., Conclusions: Previous studies were mainly focused on the functional outcome and quality of life; although related to both, arm volumes in patients with brachial plexus injuries were not analyzed before. Significant differences between the operated arm and the healthy arm volumes, as well as between the various types of palsy, found in the present study should trigger further prospective research in relation to neurophysiology, useful functional recovery and quality of life.

Social dilemmas are often shaped by actions involving uncertain returns only achievable in the future, such as climate action or voluntary vaccination. In this context, uncertainty may produce non-trivial effects. Here, we assess experimentally - through a collective risk dilemma - the effect of timing uncertainty, i.e. how uncertainty about when a target needs to be reached affects the participants' behaviors. We show that timing uncertainty prompts not only early generosity but also polarized outcomes, where participants' total contributions are distributed unevenly. Furthermore, analyzing participants' behavior under timing uncertainty reveals an increase in reciprocal strategies. A data-driven game-theoretical model captures the self-organizing dynamics underpinning these behavioral patterns. Timing uncertainty thus casts a shadow on the future that leads participants to respond early, whereas reciprocal strategies appear to be important for group success. Yet, the same uncertainty also leads to inequity and polarization, requiring the inclusion of new incentives handling these societal issues., Competing Interests: The authors declare no competing interests., (© 2020 The Authors.)

How do people decide which action to take? This question is best answered using Game Theory, which has proposed a series of decision-making mechanisms that people potentially use. In network simulations, wherein games are repeated and pay-off differences can be observed, those mechanisms often rely on imitation of successful behaviour. Surprisingly, little to no evidence has been provided about whether people actually imitate more successful opponents when altering their actions in that context. By comparing two experimental treatments wherein participants play the iterated Prisoner's Dilemma game in a lattice, we aim to answer whether more successful actions are imitated. While in the first treatment, participants have the possibility to use pay-off differences in making their decision, the second treatment hinders such imitation as no information about the gains is provided. If imitation of the more successful plays a role then there should be a difference in how players switch from cooperation to defection between both treatments. Although, cooperation and pay-off levels do not appear to be significantly different between both treatments, detailed analysis shows that there are behavioural differences: when confronted with a more successful co-player, the focal player will imitate her behaviour as the switching is related to the experienced pay-off inequality., Competing Interests: The authors declare no conflict of interest. The funding agency had no role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript, or in the decision to publish the results., (© 2020 The Authors.)

Giant cavernomas (GC) are rare lesions, with less than 50 cases reported so far. Clinical presentation usually involves epileptic seizures and less typically focal neurological deficit, due to repeated hemorrhages and GC mass effect and consequentially increased intracranial pressure. Although individual cases have been reported, due to the rarity and variable imaging appearance, GCs are usually not considered in the differential diagnosis of large hemorrhagic lesions, especially when significant mass effect is present. A 17-year-old boy presented due to severe headache, right-sided weakness, and slurred speech. Symptoms started three days before with occasional headaches, which intensified gradually. Emergency computed tomography revealed a left frontal massive heterogeneous lesion. Soon after, right-sided hemiparesis and speech impairment progressed, and the patient became drowsy with the slightly dilated left pupil. Emergency surgery was performed, and the lobed grayish lesion was entirely removed. Based on the macroscopic appearance, the surgeon assumed it was a metastasis of melanoma. Histopathologic analysis result was cavernoma. GC should be considered as an option in hemorrhagic lesions, especially in the young age population. Emergency surgery for mass lesions is not uncommon in neurosurgery; however, bleeding cavernomas are usually planned for elective surgery due to the specific approach and complications.

This paper aims to provide an overview of recent advances in the diagnosis and treatment of peripheral nerve tumors (PNTs) with regard to biological and technological nuances, and to highlight some recommendations for achieving better outcomes in the treatment of patients suffering from PNT. PNTs are probably the most challenging entity in the field of peripheral nervous system surgery. The goal of removing a nerve tumor while also preserving nerve function at the same time is often complicated, regardless of the surgeon's experience. Still, in most cases, high-quality results can be achieved upon carefully planned surgery. Clinical presentation, diagnosis, and indications for a specific type of treatment of PNTs still remain a topic of debate. Recent technological advances have led to an exponential improvement in the field with utilization of intraoperative ultrasound, neurostimulation devices, and intraoperative electrophysiological monitoring, along with the development of modern surgical techniques, whereby a multidisciplinary and individually shaped approach is necessary. CONCLUSION: These advances, however, still remain limited, and recent research is focused on the development of biological therapy. Biologically targeted therapies will emerge when there is a better understanding of the genetic and molecular mechanisms driving the development and growth of PNTs., (Copyright © 2020 by Academy of Sciences and Arts of Bosnia and Herzegovina.)

What is intuitive: pro-social or anti-social behaviour? To answer this fundamental question, recent studies analyse decision times in game theory experiments under the assumption that intuitive decisions are fast and that deliberation is slow. These analyses keep track of the average time taken to make decisions under different conditions. Lacking any knowledge of the underlying dynamics, such simplistic approach might however lead to erroneous interpretations. Here we model the cognitive basis of strategic cooperative decision making using the Drift Diffusion Model to discern between deliberation and intuition and describe the evolution of the decision making in iterated Prisoner's Dilemma experiments. We find that, although initially people's intuitive decision is to cooperate, rational deliberation quickly becomes dominant over an initial intuitive bias towards cooperation, which is fostered by positive interactions as much as frustrated by a negative one. However, this initial pro-social tendency is resilient, as after a pause it resets to the same initial value. These results illustrate the new insight that can be achieved thanks to a quantitative modelling of human behavior.

The international trade naturally maps onto a complex networks. Theoretical analysis of this network gives valuable insights about the global economic system. Although different economic data sets have been investigated from the network perspective, little attention has been paid to its dynamical behaviour. Here we take the World Input Output Data set, which has values of the annual transactions between 40 different countries of 35 different sectors for the period of 15 years, and infer the time interdependence between countries and sectors. As a measure of interdependence we use correlations between various time series of the network characteristics. First we form 15 primary networks for each year of the data we have, where nodes are countries and links are annual exports from one country to the other. Then we calculate the strengths (weighted degree) and PageRank of each country in each of the 15 networks for 15 different years. This leads to sets of time series and by calculating the correlations between these we form a secondary network where the links are the positive correlations between different countries or sectors. Furthermore, we also form a secondary network where the links are negative correlations in order to study the competition between countries and sectors. By analysing this secondary network we obtain a clearer picture of the mutual influences between countries. As one might expect, we find that political and geographical circumstances play an important role. However, the derived correlation network reveals surprising aspects which are hidden in the primary network. Sometimes countries which belong to the same community in the original network are found to be competitors in the secondary networks. E.g. Spain and Portugal are always in the same trade flow community, nevertheless secondary network analysis reveal that they exhibit contrary time evolution., Competing Interests: The authors have declared that no competing interests exist.

We have carried out a comparative analysis of data collected in three experiments on Prisoner's Dilemmas on lattices available in the literature. We focus on the different ways in which the behavior of human subjects can be interpreted, in order to empirically narrow down the possibilities for behavioral rules. Among the proposed update dynamics, we find that the experiments do not provide significant evidence for non-innovative game dynamics such as imitate-the-best or pairwise comparison rules, whereas moody conditional cooperation is supported by the data from all three experiments. This conclusion questions the applicability of many theoretical models that have been proposed to understand human behavior in spatial Prisoner's Dilemmas. A rule compatible with all our experiments, moody conditional cooperation, suggests that there is no detectable influence of interaction networks on the emergence of cooperation in behavioral experiments.

Malignant diseases of the medial part of the femur, humerus and tibia, treated with surgical removal of the affected part of the bone and prosthesis fitting special "Spacer". This type of prosthesis is made in the form of the proximal and distal components that connect by screws. The design of endoprosthesis provides without possible rotation linear relationship and allows the transfer of load from the proximal to the distal bone, but the screws that provide connection are not exposed to stress. For pro-per sizing and implementation of a special prosthesis is necessary to determine the geometric parameters of bone mass and disease and then develop a computer model of the prosthesis. Designing a special prosthesis "spacer" is a complex procedure based on the processing of diagnostic images (X-ray, CT or MRI) with the use of specialized software digitized picture elements pixels translate into voxels. In this way a geometric model contains a form of external (KORTEX), and the internal geometry of the bone (medullary canal). On the basis of such a developed computer models is possible accurately determine the part of the bone that is necessary to remove, and the size of medullary canal space that is built into proximal or distal component of special endoprosthesis "Spacer".