Spatial and temporal variations of snow cover in the forest area of middle and high latitude of Northern Hemisphere

Snow cover is an important part of cryosphere and the most seasonally changing land surface cover, which is sensitive to climate change. Previous studies showed that climate warming has already altered the extent and phenology of snow cover, which influences the plant phenology of the forest ecosystem. This research investigates the spatial distribution and temporal trend of snow cover in the forest area of mid and high latitude in the Northern Hemisphere (50°N-90°N,180°W-180°E) based on a satellite-derived snow dataset. Results showed that the spatial distribution of snow cover exhibits a latitudinal gradientin the mid and high latitudes of the Northern Hemisphere. The snow cover onset week (SCOW) and snow cover end week (SCEW) shortened significantly at a rate of 0.23 weeks/10 yr. and 0.48 weeks/10 yr., respectively (P<0.05). Cold season (CS) and snow cover persistence week (SCPW) shortened at a rate of 0.25 weeks/10 yr. and 0.16 weeks/10 yr. 19.62% of the study area showed a trend of a significant advance in SCOW, and 1.36% showed a trend of significant delay (P<0.05). For SCEW, 44.91% of regions showed significant advance and 1.91% of regions showed significant delay (P<0.05). CS was a significantly shorted trend (P<0.05) in 16.95% of the study area and showed a significantly extended trend (P<0.05) in 3.76% of the area. SCPW and CS were similar but different, indicating that transient snowfall exists in parts of the study area.

Effects of the COVID-19 Pandemic on Treatment Efficiency for Traumatic Brain Injury in the Emergency Department: A Multicenter Study in Taiwan

The coronavirus disease 2019 (COVID-19) pandemic has impacted emergency department (ED) practice, including the treatment of traumatic brain injury (TBI), which is commonly encountered in the ED. Our study aimed to evaluate TBI treatment efficiency in the ED during the COVID-19 pandemic. A retrospective observational study was conducted using the electronic medical records from three hospitals in metropolitan Taipei, Taiwan. The time from ED arrival to brain computed tomography (CT) and the time from ED arrival to surgical management were used as measures of treatment efficiency. TBI treatment efficiencies in the ED coinciding with a small-scale local COVID-19 outbreak in 2020 (P1) and large-scale community spread in 2021 (P2) were compared against the pre-pandemic efficiency recorded in 2019. The interval between ED arrival and brain CT was significantly shortened during P1 and P2 compared with the pre-pandemic interval, and no significant delay between ED arrival and surgical management was found, indicating increased treatment efficiency for TBI in the ED during the COVID-19 pandemic. Minimizing viral spread in the community and the hospital is vital to maintaining ED treatment efficiency and capacity. The ED should retain sufficient capacity to treat older patients with serious TBI during the COVID-19 pandemic.

SRSF2-P95Hdelays Myelofibrosis Development through Altered JAK/STAT Signaling in JAK2-V617F Megakaryocytes

Background: The gain-of-function JAK2 V617F mutant is the most common driver mutation identified in myeloproliferative neoplasms (MPNs). Additional somatic variants, also found in other malignant hemopathies, are detected in primary myelofibrosis (MF) and supposed to contribute to fibrosis or leukemia development. One of these mutations affects SRSF2, a gene encoding a component of the splicing machinery. SRSF2 heterozygous mutation mainly affects the proline 95 residue of the protein. Its association with JAK2 V617F correlates with a reduced leukemia free survival. Whether and how SRSF2 P95 variants could favor fibrosis development in JAK2 V617F cells remained unknown. Methods & Results: To investigate how homozygous Jak2 V617F and heterozygous Srsf2 P95H could interact in the hematopoietic tissue, we generated conditional knock-in mice in which the CreERt recombinase expression was driven by the HSC-Scl promoter leading to Jak2 V617F and/or Srsf2 P95H hematopoietic-specific expression upon tamoxifen induction. Srsf2 P95H mutation initially exhibited limited effect on Jak2 V617F-induced polycythemia vera (PV) only slightly reducing erythrocytosis and leukocytosis (through a previously described decrease in B220 + B cell number). The expansion of hematopoietic stem cells (SLAM), multipotent progenitors (MPP) and megakaryocyte progenitors (MKP) observed in Jak2 V617F mice was not affected by Srsf2 status. However, while platelet count was decreasing in Jak2 V617F alone mice at later time point due to fibrosis development, Srsf2 P95H/Jak2 V617F combination further increased platelet counts correlating with a significant delay in the development of myelofibrosis. Bone marrow cells (BM) were transplanted into lethally irradiated recipient mice together with GFP-positive wild-type competitor cells and tamoxifen was administrated after transplantation. Double mutant cells initially demonstrated a limited competitive advantage over wild-type cells as compared to Jak2 V617F-only cells. However, serial transplantation revealed a rapid exhaustion of Jak2 V617F single mutant cells leading to lethal pancytopenia, which was not observed in animals transplanted with Jak2 V617F/Srsf2 P95H double mutant cells. As both monocytes and megakaryocytes (MK) were involved in fibrosis development, we further explored the role of these two cell populations. Spectral flow analysis of monocyte subsets in peripheral blood and BM failed to detect any significant change in double compared to single mutant animals. In contrast, double-mutant mice presented a significant delay in MK maturation with normalized expression of c-Mpl and ploidy. Using mass cytometry, we found ex vivo a higher proportion of MKP and MK expressing high levels of P-Stat5 in Jak2 V617F mice, which the addition of Srsf2 P95H tend to reduce, suggesting an altered Mpl/Jak2 signaling pathway. To validate the hypothesis that Srsf2 P95H negatively interfere with Jak2-mediated signaling in MK, we injected high dose of the thrombopoietin-mimetic romiplostim in mice transplanted with wild-type or Srsf2 P95H BM. Both thrombocytosis and myelofibrosis were significantly reduced in Srsf2 P95H transplanted animals. To further decipher the mechanism by which Srsf2 P95H could alter cell signaling, we performed bulk RNA sequencing on sorted MK. Pathway analysis using gene set enrichment analysis identified mostly a down-regulation of signaling pathways, including JAK/STAT signaling, in Jak2 V617F/Srsf2 P95H compared to Jak2 V617F single mutant cells. Further analysis of splicing events in Srsf2 P95H mutant cells identified an increased exon 14 skipping in Jak2, which was validated by RT-qPCR. Summary: Contrary to EZH2 mutation that promotes JAK2 V617F-induced myelofibrosis in mouse models, heterozygous Srsf2 P95H delays myelofibrosis development in Jak2 V617F-transgenic mice. Srsf2 P95H co-mutation prevents the clonal exhaustion induced by serial transplantation of JAK2 V617F BM cells. This effect is associated with a reduced signaling in MK, which may involve abnormal splicing of signaling components including Jak2 exon 14 skipping. Disclosures Abdel-Wahab: H3B Biomedicine: Consultancy, Research Funding; Foundation Medicine Inc: Consultancy; Merck: Consultancy; Prelude Therapeutics: Consultancy; LOXO Oncology: Consultancy, Research Funding; Lilly: Consultancy; AIChemy: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Envisagenics Inc.: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees.

Four unusual sinonasal and sinorbital lesions: a case series

<p class="abstract">Presentations of Sino nasal lesions may be indistinguishable and therefore represent diagnostic and therapeutic dilemma due similarities of non-neoplastic and neoplastic lesions at initial presentation may lead to a significant delay in the diagnosis. This case series has been reported to through light on four different case scenarios that presented to us, their diagnosis and management. This was a case series of four unusual cases of the sinonasal and sinoorbital region that presented with symptoms of nasal obstruction, rhinnorhea, epistaxis, radiological and diagnostic nasal endoscopy was performed. Using functional endoscopic sinus surgery and lynch Howarth method the lesions were excised. As sino nasal and sinoorbital lesions present with similar clinical features accurate diagnostic procedures such as nasal endoscopy and radiological investigations, histopathological investigations play an important role in the management of the lesions. </p>

Effect of Choice Bracketing on Risk Aggregation in Repeated-Play Gambles With no Feedback

Aggregating the risk of a series of decisions reduces the overall risk compared to when each decision is considered individually—the logic behind diversified investment strategies. Most experimental research on a series of risky decisions provides participants with immediate feedback for each individual choice before presenting the subsequent gamble—a task-structure that inhibits the possibility of risk aggregation. In real-life business decisions, feedback is usually not seen until a significant delay with many more business decisions made in the interim. This decision-making sequence has the potential for systematic risk aggregation. However, it is unclear how people determine what decisions cluster together such that those decisions’ risks become aggregated. In the current work, we presented experimental participants a series of scenarios describing potential investments and investigated multiple ways to support clustering or bracketing choices together. We found that showing a distribution of outcome probabilities without inter-trial feedback reduced risk aversion. Further, we found mixed evidence for an effect of similarity of projects, and found only minimal evidence that viewing projects together and awareness of the number of projects encourages aggregation. These results suggest that risk aggregation is hard to facilitate, at least in laypeople, without first aggregating the options for them.

Comparison of Haloperidol versus Midazolam for Prevention of Sevoflurane Emergence Agitation in Pediatric patients undergoing Inguinal Surgeries

Background Emergence agitation (EA) in children early after sevoflurane anaesthesia is a common postoperative problem, with incidence ranging up to 80%, It is characterized by behavior that can include crying, disorientation, excitation and delirium, several drugs have been tried in this regard including but not limited to propofol, midazolam, ketamine and ketorolac among other drugs. Aim of the Work To compare the effect of intravenous Midazolam vs intravenous Haloperidol & in prevention of Sevoflurane Emergence Agitation in pediatric patients undergoing Inguinal Surgeries. Patients and Methods This prospective randomized study was done after approval of institutional ethics committee in Ain Shams university Hospitals for 6 months and obtaining an informed written consent from parents. It was designed to include sixty-two pediatric patients, aged 3 to 12 years of both genders, with physical status ASA Ι and ASA ІІ. All surgical procedures were elective of an expected duration of 30 - 60 minutes e.g. inguinal hernia repair, hydrocele, orcheopexy under general anesthesia and caudal block to relief pain. All operations were performed in supine position. Results Our study was applied on age group between 3- 12 years old Haloperidol was associated with 24% EA and was also associated with significant delay in eye opening and time till discharge from PACU when compared to Midazolam. Conclusion I.V Midazolam is more efficient than I.V Haloperidol for prevention of Sevoflurane Emergence agitation in pediatric patients undergoing inguinal surgeries.

SIN-like pathway kinases regulate the end of mitosis in the methylotrophic yeast Ogataea polymorpha

The Mitotic exit network (MEN) is a conserved signalling pathway essential for termination of mitosis in the budding yeast Saccharomyces cerevisiae. All MEN components are highly conserved in the methylotrophic budding yeast Ogataea polymorpha, except for Cdc15 kinase. Amongst O. polymorpha protein kinases that have some similarity to ScCdc15, only two had no other obvious homologues in S. cerevisiae and these were named OpHCD1 and OpHCD2 for homologue candidate of ScCdc15. A search in other yeast species revealed that OpHcd2 has an armadillo type fold in the C-terminal region as found in SpCdc7 kinases of the fission yeast Schizosaccharomyces pombe, which are homologues of ScCdc15; while OpHcd1 is homologous to SpSid1 kinase, a component of the Septation Initiation Network (SIN) of S. pombe not present in the MEN. Since the deletion of either OpHCD1 or OpHCD2 resulted in lethality under standard growth conditions, conditional mutants were constructed by introducing an ATP analog sensitive mutation. For OpHCD2, we constructed and used new genetic tools for O. polymorpha that combined the Tet promoter and the improved auxin-degron systems. Conditional mutants for OpHCD1 and OpHCD2 exhibited significant delay in late anaphase and defective cell separation, suggesting that both genes have roles in mitotic exit and cytokinesis. These results suggest a SIN-like signalling pathway regulates termination of mitosis in O. polymorpha and that the loss of Sid1/Hcd1 kinase in the MEN occurred relatively recently during the evolution of budding yeast.

How a pediatric neuro-oncology unit was managed in Madrid during the first wave of the COVID-19 pandemic

Introduction: During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, infection prevention measures were enforced at our Pediatric Neuro-Oncology unit. Methods: A retrospective study analyzing patients booked in this unit during lockdown was performed to describe its performance. Results: There were 438 consultations for 123 patients (320 on-site/118 telephone). Eight new diagnoses were made, with one significant delay. Only one patient tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Delay in imaging testing occurred in 15 patients. Chemotherapy was delayed in one case. There were no delays in radiotherapy. Conclusions: Measures implemented were effective in minimizing the risk of COVID-19 infection, achieving continuity in diagnoses and treatment, and avoiding delays that could impact survival.

Preventing Environmental Disasters in Investment under Uncertainty

The paper considers a firm that has the option to invest in a project with an unknown profitability, which is affected by general market uncertainty. The project has the adverse effect that it can cause environmental damage. In case the firm has the option to undertake preventive investment at the time of market entry, we get that preventive investment is significant when (i) the project revenue is large, (ii) the environmental incidents potentially cause a huge reduction of firm value, and (iii) when preventive investment substantially decreases the probability of environmental damage occurrence. The optimality of such a preventive investment results in a significant delay of the project investment. When the firm has the possibility to invest in the project first and do the preventive investment later, this will accelerate the project investment and will result in a larger preventive investment when it indeed will decide to do that one later.

Delayed buckling of spherical shells due to viscoelastic knockdown of the critical load

We performed dynamic pressure buckling experiments on defect-seeded spherical shells made of a common silicone elastomer. Unlike in quasi-static experiments, shells buckled at ostensibly subcritical pressures, i.e. below the experimentally determined critical load at which buckling occurs elastically, often following a significant delay period from the time of load application. While emphasizing the close connections to elastic shell buckling, we rely on viscoelasticity to explain our observations. In particular, we demonstrate that the lower critical load may be determined from the material properties, which is rationalized by a simple analogy to elastic spherical shell buckling. We then introduce a model centred on empirical quantities to show that viscoelastic creep deformation lowers the critical load in the same predictable, quantifiable way that a growing defect would in an elastic shell. This allows us to capture how both the deflection at instability and the time delay depend on the applied pressure, material properties and defect geometry. These quantities are straightforward to measure in experiments. Thus, our work not only provides intuition for viscoelastic behaviour from an elastic shell buckling perspective but also offers an accessible pathway to introduce tunable, time-controlled actuation to existing mechanical actuators, e.g. pneumatic grippers.