Search

Mafic intrusions, lava flows, and felsic plutons in southwestern Laurentia have been hypothesized to be associated with the emplacement of a late Mesoproterozoic (Stenian Period) large igneous province. Improved geochronologic data resolve distinct episodes of mafic magmatism in the region. The ca. 1,098 Ma main pulse of southwestern Laurentia large igneous province (SWLLIP) magmatism is recorded by mafic intrusions across southeastern California to central Arizona. A younger episode of volcanism resulted in eruptions that formed the ca. 1,082 Ma Cardenas Basalt, which is the uppermost unit of the Unkar Group in the Grand Canyon. With the updated geochronological constraints, we develop new paleomagnetic data from mafic sills in the SWLLIP. Overlapping poles between the Death Valley sills and rocks of similar age in the Midcontinent Rift are inconsistent with large-scale Cenozoic vertical axis rotations in Death Valley. We also develop a new paleomagnetic pole from the ca. 1,082 Ma Cardenas Basalt (pole longitude = 183.9°E, pole latitude = 15.9°N, (Formula presented.) = 7.4°, N = 18). The new paleomagnetic data are consistent with the pole path developed from time-equivalent rocks of the Midcontinent Rift, supporting interpretations that changing pole positions are the result of rapid equatorward motion. These data add to the record of Laurentia's rapid motion from ca. 1,110 to 1,080 Ma that culminated in collisional Grenvillian orogenesis and the assembly of Rodinia.

While thermochronological studies have constrained the landscape evolution of several of the crustal blocks of West and East Antarctica, the tectono-thermal evolution of the Ellsworth Mountains remains relatively poorly constrained. These mountains are among the crustal blocks that comprise West Antarctica and exhibit an exceptionally well-preserved Palaeozoic sedimentary sequence. Despite the seminal contribution of Fitzgerald and Stump (1991), who suggested an Early Cretaceous uplift event for the Ellsworth Mountains, further thermochronological studies are required to improve the current understanding of the landscape evolution of this mountain chain. We present new zircon (U–Th) / He (ZHe) ages, which provide insights into the landscape evolution of the Ellsworth Mountains. The ZHe ages collected from near the base and the top of the sequence suggest that these rocks underwent burial reheating after deposition. A cooling event is recorded during the Jurassic–Early Cretaceous, which we interpret as representing exhumation in response to rock uplift of the Ellsworth Mountains. Moreover, our results show that while ZHe ages at the base of the sequence are fully reset, towards the top ZHe ages are partially reset. Uplift and exhumation of the Ellsworth Mountains during the Jurassic–Early Cretaceous was contemporaneous with the rotation and translation of this crustal block with respect to East Antarctica and possibly the Antarctic Peninsula. Furthermore, this period is characterized by widespread extension associated with the disassembly and breakup of Gondwana, with the Ellsworth Mountains playing a key role in the opening of the far southern Atlantic. Based on these results, we suggest that uplift of the Ellsworth Mountains during the disassembly of Gondwana provides additional evidence for major rearrangement of the crustal blocks between the South American, African, Australian and Antarctic plates. Finally, uplift of the Ellsworth Mountains commenced during the Jurassic, which predates the Early Cretaceous uplift of the Transantarctic Mountains. We suggest that the rift-related exhumation of the Ellsworth Mountains occurred throughout two events: (i) a Jurassic uplift associated with the disassembly of southwestern Gondwana and (ii) an Early Cretaceous uplift related with the separation between Antarctica and Australia, which is also recorded in the Transantarctic Mountains.

ABSTRACTThe genetically engineered bollworm-resistant Bt cotton hybrid varieties offer opportunities for reducing crop losses and enhancing productivity. In Eastern Africa region, Sudan, Ethiopia, and Kenya have approved and released Bt cotton in 2012, in 2018, and in 2019, respectively. The region has potential to grow cotton in over 5 million hectares. For commercial plantings in Ethiopia, Sudan and Kenya, hybrid Bt cotton seeds have been imported from India. Due to the COVID-19 pandemic-induced supply chain disruptions, high shipment costs, bureaucratic procedures for importing seeds, and foreign exchange shortages, farmers have not been able to access Bt cotton seeds. Stakeholders are seeking local production of seeds to provide sustainable access by farmers at affordable cost. Country case studies reveal the importance of enhancing capacity for local seed production and extension advisory services. Revival of the cotton sector needs enhanced public-private partnerships to pave the way for sustainable seeds access in the region.

Abstract Introduction Treatment with oral retinoids can be effective in patients with congenital ichthyosis (CI) but may be associated with clinically significant laboratory changes. In this Phase 2b CONTROL study analysis, we characterize the effects of TMB-001, a novel topical isotretinoin formulation, on laboratory values in participants with X-linked recessive (XLRI) and autosomal recessive lamellar (ARCI-LI) ichthyosis at 12 weeks. Methods A randomized, double-blind, vehicle-controlled, Phase 2b study was conducted with participants ≥ 9 years of age with confirmed XLRI and ARCI-LI. Participants were randomized 1:1:1 and stratified by CI subtype to receive TMB-001 0.05%:TMB-001 0.1%:vehicle twice daily for 12 weeks. Laboratory analyses were performed at screening and Week 12. Results Among 33 enrolled participants (TMB-001 0.05% n = 11, TMB-001 0.1% n = 10, and vehicle n = 12), 52% had ARCI-LI and 48% had XLRI. At 12 weeks, there were single reports of anemia, neutropenia, leukopenia, lymphocytosis, and leukocytosis after vehicle treatment; neutropenia was reported in one participant receiving TMB-001 0.1%. There were single reports of abnormal biochemistry values—liver enzymes, creatinine, urea nitrogen, hyperkalemia, and hyperproteinemia—across treatment cohorts. Non-fasting hyperglycemia was observed in three participants receiving TMB-001 0.1% and one participant receiving vehicle. Urinalysis abnormalities reported in > 1 participant included urobilinogen (TMB-001 0.1% n = 2, vehicle n = 2), protein (TMB-001 0.1% n = 3, vehicle n = 2), and leukocyte esterase (TMB-001 0.1% n = 2). Laboratory parameter changes were asymptomatic and did not require study discontinuation or drug withdrawal. Conclusion There were no clinically significant laboratory changes in participants receiving TMB-001 isotretinoin ointment through 12 weeks of treatment, which differs from reported results for systemic isotretinoin. Trial Registration: NCT04154293.

Background: Online helplines have shown a high acceptance, feasibility, and usability, especially with young people. Helplines usually aim to provide one-time crisis intervention; however, there are users who frequently use such services, tying a disproportionately large proportion of service capacities. To date, there is no research on the characterization of frequent users of online helplines. Therefore, the aim of the present study is to characterize frequent chatters in a chat-based counseling context. Methods: This cross-sectional study retrospectively analyzed anonymous data of users who approached the German messenger-based psychological chat counseling service krisenchat between May 2020 and July 2021 (N = 6657), with a focus on frequent users - the “frequent chatters”. Frequent chatters were defined as those who received an above average (M + 2 ∗ SD) amount of messages from counselors over a period of one week and had at least 7 days of contact with the service over the entire data collection period. Chi-square-tests and Mann-Whitney-U tests were conducted to identify differences between frequent users and the population of all users. Results: In total, n = 99 (1.5 %) users met the definition for frequent chatters and accounted for roughly a tenth (9.85 %) of all chats of the service. The mean frequent chatter was 17 years old (M = 17.29, SD = 3.56), female (n = 78, 82.1 %), and approached the service in the late afternoon (M = 5:00 pm, SD = 5:25 h). Compared to the general user population, frequent chatters reported significantly more severe concerns to counselors, of which 81.8 % included psychiatric symptoms, such as suicidality (43.4 %) and non-suicidal self-injury (41.4 %). In addition, frequent chatters were significantly more likely to contact krisenchat alongside the use of other professional help services. Further, frequent chatters wrote significantly longer and more messages during the counseling process and within a session than the general user population of krisenchat. Compared to the general user population, frequent chatters did not differ in their satisfaction with the service. Conclusion: Frequent users are known from telephone helplines and are also represented in a chat-based context. Compared to the general user population, they are more likely to report serious mental health conditions and half of them currently receive professional help, suggesting a high need for social support. In light of the increasing development of chat-based helplines, there is a need for further research on frequent chatters to develop tailored counseling strategies for their needs and to analyze options for an optimized service provision. Study registration: DRKS00026671

A fluorinated thiol was systematically investigated against a diverse set of –ene- and –yne-bearing imidazole and imidazolium substrates in the pursuit of new cation-fluorinated, omniphobic (hydrophobic and oleophobic) ionic liquids for aerospace applications. Compounds were prepared using UV-initiated click chemistry at quantitative conversion and purified with relative ease. Seven ionic liquids were synthesized and have isolated yields ranging from 74% to >99%. Five of the new cation-fluorinated ionic liquids are hydrophobic and two are liquids at room temperature. In addition to hydrophobicity, the seven ionic liquids’ solubilities were qualitatively examined across a wide spectrum of conventional organic solvents. Of note, the majority of the prepared ionic liquids are insoluble in water and hexanes yet soluble in methanol, acetone, acetonitrile, and dichloromethane. In addition to intriguing solubility properties, the ionic liquids in this study have high densities without the incorporation of heavy atoms, ranging from 1.596 to 1.924 g cm−3. The fluorinated salts also show good short-term thermal stability in air, with decomposition temperatures ranging from 215 °C to 320 °C. Other relevant characterization methods include spectroscopy, thermal analysis, and physical property measurements where appropriate. The X-ray crystal structure of a divalent, cation-fluorinated ionic liquid from this study was also obtained and shows unique fluorous domains in the extended structure, providing valuable insight into the materials’ physical properties. This work highlights a family of compounds moving towards omniphobic ionic liquids yielding potential possibilities for future applications.

A fluorinated thiol was systematically investigated against a diverse set of –ene- and –yne-bearing imidazole and imidazolium substrates in the pursuit of new cation-fluorinated, omniphobic (hydrophobic and oleophobic) ionic liquids for aerospace applications. Compounds were prepared using UV-initiated click chemistry at quantitative conversion and purified with relative ease. Seven ionic liquids were synthesized and have isolated yields ranging from 74% to >99%. Five of the new cation-fluorinated ionic liquids are hydrophobic and two are liquids at room temperature. In addition to hydrophobicity, the seven ionic liquids’ solubilities were qualitatively examined across a wide spectrum of conventional organic solvents. Of note, the majority of the prepared ionic liquids are insoluble in water and hexanes yet soluble in methanol, acetone, acetonitrile, and dichloromethane. In addition to intriguing solubility properties, the ionic liquids in this study have high densities without the incorporation of heavy atoms, ranging from 1.596 to 1.924 g cm−3. The fluorinated salts also show good short-term thermal stability in air, with decomposition temperatures ranging from 215 °C to 320 °C. Other relevant characterization methods include spectroscopy, thermal analysis, and physical property measurements where appropriate. The X-ray crystal structure of a divalent, cation-fluorinated ionic liquid from this study was also obtained and shows unique fluorous domains in the extended structure, providing valuable insight into the materials’ physical properties. This work highlights a family of compounds moving towards omniphobic ionic liquids yielding potential possibilities for future applications.

BackgroundThe literature indicates a negative impact on the mental health of university students during the COVID-19 pandemic. It remains unclear if this negative impact persists even after lockdown measures are lifted. The current study therefore investigates the mental health status of students by drawing on two previous studies the present study seeks to investigate differences in the mental health status across three time points.MethodsA cross-sectional, anonymous online survey among students of six universities was conducted between April and May 2022 (N = 5,510). Symptoms of depression, anxiety, hazardous alcohol use and eating disorders as well as social and emotional variables were assessed utilizing standardized instruments. Risk- and protective factors for severity of depressive and anxiety symptoms were investigated using multiple regression models. Differences in e.g., symptoms of depression across three time points were assessed with one-way analysis of variance.ResultsMore than one third of students exhibited clinically relevant symptoms of depression (35.5%), hazardous alcohol use (33.0–35.5% depending on gender) or anxiety disorder (31.1%). Taken together, almost two out of three (61.4%) students reported clinically relevant symptoms in at least one of the aforementioned symptom patterns, while almost one fifth of students reported suicidal ideation or thoughts of self-harm (19.6%). Higher perceived stress and loneliness significantly predicted higher levels of depressive symptoms, while resilience and social support were identified as protective factors. Compared to 2020 and 2021, levels of depressive symptoms were significantly reduced in 2022, levels of hazardous alcohol consumption showed a small but significant increase from 2021 to 2022. Worryingly, prevalence of suicidal ideation was the highest yet, being significantly higher than in 2020 (14.5%) and 2021 (16.5%).ConclusionThese results confirm previous results that the pandemic had and still has a negative impact on the mental health of university students. The present study broadens this view by the fact that some areas seem to recover quicker, while others seem to increase worryingly. Especially the persistent rise in suicidal ideation from 2020 to 2021 and to 2022, a constant reduction in reported social support and associated perceived loneliness is concerning. The claim for low-threshold and accessible mental health support for university students remains the same as in the beginning of the pandemic.

Quaternary glaciations have significantly impacted the midcontinental North American landscape, leaving behind a proglacial sediment record of glacial lake deposits, glacio-fluvial sand and gravel, and windblown loess. This paper aims to expand upon a previous study using detrital zircon provenance analysis to investigate midcontinental North American loess provenance in relation to the glacial history of the southern Laurentide ice sheet during the middle to late Pleistocene. The study incorporates previously published detrital zircon data from last glacial tills (representing the Huron-Erie Lobe, Lake Michigan Lobe, Green Bay Lobe, Superior Lobe, Des Moines Lobe, and James Lobe), middle to late Pleistocene loess from several sites along the Illinois and Mississippi River valleys, and suspended sediment load inputs from the Missouri River and Arkansas River. A statistical mixing model (DzMix version 2.2) was used to estimate the relative proportions of glacial and nonglacial sources to Wisconsin Episode, Illinois Episode, and pre-Illinois Episode age loess. We show that mixing models that include the modern suspended sediment loads of the Missouri and Arkansas Rivers significantly improve (up to 23% increase in cross-correlation value) the source characterization of Wisconsin Episode (last glacial) and Illinois Episode (penultimate glacial) loess deposits within the Mississippi River drainage basin. These river sources are dominant inputs for certain loess sites (as much as 51%), but their relative contributions are not static across time and space, which has implications for temporal and spatial differences in relative sediment source estimates and glacial and fluvial sediment transport evolution. Specifically, differences in relative sediment proportion estimates among Wisconsin, Illinois, and pre-Illinois Episode loess support previous evidence for the persistence of a Quebec-Labrador ice dome source through multiple glacial cycles, even with the inclusion of river sources in updated mixing models. Illinois and pre-Illinois Episode loess in the southern portion of our study area received ~20% detrital zircon input from sources similar to the present-day Missouri and Arkansas Rivers, suggesting that these river systems were contributing a significant amount of detritus to the lower Mississippi River valley region during the middle Pleistocene. [ABSTRACT FROM AUTHOR]

Deep-time thermochronology by the zircon (U-Th)/He (ZHe) method is an emerging field of study with promise for constraining Precambrian rock thermal and exhumation histories. The Grand Canyon provides an opportunity to further explore this method because excellent geologic constraints can be integrated with multiple thermochronometers to address important questions about the spatial variability of basement erosion below the sub-Cambrian Great Unconformity composite erosional surface. In this study, we synthesize new ZHe results (n = 26) and published (n = 77) ZHe data with new Kfeldspar 40Ar/39Ar data and models (n = 4) from Precambrian basement rocks of the Grand Canyon, USA. We use HeFTy and QTQt thermal history modeling to evaluate the ability of the individual ZHe and Kfeldspar 40Ar/39Ar thermochronometric data sets to resolve Precambrian thermal histories and compare those results with jointly modeled data using the QTQt software. We also compare Precambrian basement thermal histories of the eastern and western Grand Canyon, where the eastern Grand Canyon has ~4 km of Grand Canyon Supergroup strata deposited and preserved, and the western Grand Canyon, where the Supergroup was either never deposited or not preserved. In all locations, models constrained only by ZHe data have limited resolving power for the past ~600 m.y., compared to models that combine K-feldspar 40Ar/39Ar and ZHe data, which extends the recorded history into the Mesoproterozoic. Our model results suggest that two regional basement unroofing events occurred. A ca. 1350-1250 Ma cooling event is interpreted to record basement exhumation from depths of ~10 km, and a second cooling episode (~200-100 °C total) records exhumation from a depth of ~3 km to 7 km to near-surface conditions between ca. 600 Ma and 500 Ma. Easternmost Grand Canyon models suggest that the preserved maximum ~4 km thickness of the Grand Canyon Supergroup (with burial heating at ~100 °C) approximates the total original Mesoproterozoic and Neoproterozoic stratal thickness. Whether these Supergroup rocks were present and then eroded in the western Grand Canyon, as suggested by regional geologic studies, or were never deposited is not constrained by thermochronological data. [ABSTRACT FROM AUTHOR]

Background: Current evidence suggests that a significant proportion of university students are affected by mental disorders and suicidal ideation. Despite this, a treatment gap exists. Therefore, the present study assessed students’ knowledge and past use of on- and off-campus mental health services and help-seeking intentions. Furthermore, resilience was investigated as a potential barrier to help-seeking behavior. Methods: Data were collected between April and May 2022 from N = 5510 students from Saxony, Germany. To compare dependent variables, subgroups were computed according to students’ mental health status. Variables were assessed using standardized questionnaires. Chi-square tests were used for comparisons between groups. Multiple regression models were used to investigate the influence of resilience on help-seeking behavior. Results: Between 34 and 38% (depending on the subgroup) of participants indicated that they were not aware of their universities’ psychosocial counseling services. Furthermore, between 17 and 19% of participants indicated that they were not willing to seek help from professional mental health services. Finally, the previously found negative effect of resilience on help-seeking behavior was confirmed. Conclusion: The results showed a lack of awareness regarding universities’ mental health services and a treatment gap among university students. Universities and healthcare providers need to educate students about mental health services and how to access them. Further research is needed to elucidate the differential impact of resilience on mental health and help-seeking.

Parkinson's disease is characterized by the progressive loss of midbrain dopamine neurons. Dopamine replacement therapy with levodopa alleviates parkinsonian motor symptoms but is complicated by the development of involuntary movements, termed levodopa-induced dyskinesia (LID). Aberrant activity in the striatum has been hypothesized to cause LID. Here, to establish a direct link between striatal activity and dyskinesia, we combine optogenetics and a method to manipulate dyskinesia-associated neurons, targeted recombination in active populations (TRAP). We find that TRAPed cells are a stable subset of sensorimotor striatal neurons, predominantly from the direct pathway, and that reactivation of TRAPed striatal neurons causes dyskinesia in the absence of levodopa. Inhibition of TRAPed cells, but not a nonspecific subset of direct pathway neurons, ameliorates LID. These results establish that a distinct subset of striatal neurons is causally involved in LID and indicate that successful therapeutic strategies for treating LID may require targeting functionally selective neuronal subtypes.