bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent advances in the formulation of PLGA microparticles for controlled drug delivery
Authors: Lagreca Elena , Onesto Valentina , Di Natale Concetta , La Manna Sara , Netti Paolo Antonio , Vecchione Raffaele
Published: October 2020

Polymeric microparticles (MPs) are recognized as very popular carriers to increase the bioavailability and bio-distribution of both lipophilic and hydrophilic drugs. Among different kinds of polymers, poly-(lactic-co-glycolic acid) (PLGA) is one of the most accepted materials for this purpose, because of its biodegradability (due to the presence of ester linkages that are degraded by hydrolysis in aqueous environments) and safety (PLGA is a Food and Drug Administration (FDA)-approved compound). Moreover, its biodegradability depends on the number of glycolide units present in the structure, indeed, lower glycol content results in an increased degradation time and conversely a higher monomer unit number results in a decreased time. Due to this feature, it is possible to design and fabricate MPs with a programmable and time-controlled drug release. Many approaches and procedures can be used to prepare MPs. The chosen fabrication methodology influences size, stability, entrapment efficiency, and MPs release kinetics. For example, lipophilic drugs as chemotherapeutic agents (doxorubicin), anti-inflammatory non-steroidal (indomethacin), and nutraceuticals (curcumin) were successfully encapsulated in MPs prepared by single emulsion technique, while water-soluble compounds, such as aptamer, peptides and proteins, involved the use of double emulsion systems to provide a hydrophilic compartment and prevent molecular degradation. The purpose of this review is to provide an overview about the preparation and characterization of drug-loaded PLGA MPs obtained by single, double emulsion and microfluidic techniques, and their current applications in the pharmaceutical industry.

Graphic abstract
Viscosity solutions for the crystalline mean curvature flow with a nonuniform driving force term
Authors: Giga Yoshikazu , Požár Norbert
Published: October 2020

A general purely crystalline mean curvature flow equation with a nonuniform driving force term is considered. The unique existence of a level set flow is established when the driving force term is continuous and spatially Lipschitz uniformly in time. By introducing a suitable notion of a solution a comparison principle of continuous solutions is established for equations including the level set equations. An existence of a solution is obtained by stability and approximation by smoother problems. A necessary equi-continuity of approximate solutions is established. It should be noted that the value of crystalline curvature may depend not only on the geometry of evolving surfaces but also on the driving force if it is spatially inhomogeneous.
Frame It Again
Authors: Bermúdez José Luis
Published: October 2020

Framing effects are everywhere. An estate tax looks very different to a death tax. Gun safety seems to be one thing and gun control another. Yet, the consensus from decision theorists, finance professionals, psychologists, and economists is that frame-dependence is completely irrational. This book challenges that view. Some of the toughest decisions we face are just clashes between different frames. It is perfectly rational to value the same thing differently in two different frames, even when the decision-maker knows that these are really two sides of the same coin. Frame It Again sheds new light on the structure of moral predicaments, the nature of self-control, and the rationality of co-operation. Framing is a powerful tool for redirecting public discussions about some of the most polarizing contemporary issues, such as gun control, abortion, and climate change. Learn effective problem-solving and decision-making to get the better of difficult dilemmas.
Jihadists of North Africa and the Sahel
Authors: Thurston Alexander
Published: October 2020

Jihadist movements have claimed that they are merely vehicles for the application of God's word, distancing themselves from politics, which they call dirty and manmade. Yet on closer examination, jihadist movements are immersed in politics, negotiating political relationships not just with the forces surrounding them, but also within their own ranks. Drawing on case studies from North Africa and the Sahel - including Algeria, Libya, Mali, Niger, Burkina Faso, and Mauritania - this study examines jihadist movements from the inside, uncovering their activities and internal struggles over the past three decades. Highlighting the calculations that jihadist field commanders and clerics make, Alexander Thurston shows how leaders improvise, both politically and religiously, as they adjust to fast-moving conflicts. Featuring critical analysis of Arabic-language jihadist statements, this book offers unique insights into the inner workings of jihadist organisations and sheds new light on the phenomenon of mass-based jihadist movements and proto-states.
Gender and Christian Ethics
Authors: Thatcher Adrian
Published: October 2020

In this book, Adrian Thatcher offers fresh theological arguments for expanding our understanding of gender. He begins by describing the various meanings of gender and depicts the relations between women and men as a pervasive human and global problem. Thatcher then critiques naive and harmful theological accounts of sexuality and gender as binary opposites or mistaken identities. Demonstrating that the gendered theologies of Hans Urs von Balthasar and Karl Barth, as well as the Vatican's “war on gender” rest on questionable binary models, he replaces these models with a human continuum that allows for sexual difference without assuming “opposite sexes” and normative sexualities.  Grounded in core Christian doctrines, this continuum enables a full theological affirmation of LGBTIQ people. Thatcher also addresses the excesses of the male/female binary in secular culture and outlines a hermeneutic that delivers justice and acceptance instead of sexism and discrimination.
Building the Aboriginal Conference Settlement Suite: Hope and Realism in Law as a Tool for Social Change
Authors: Goldbach Toby S.
Published: October 2020

In 2014, the provincial government unveiled a new courthouse in Thunder Bay, Ontario, featuring a conference area designed to emulate an Anishinaabe roundhouse. The “Aboriginal Conference Settlement Suite” epitomizes efforts to support Indigenous justice within the criminal justice system. However, despite similar efforts in the past, the circumstances of Indigenous peoples in Canada have not improved. This ongoing commitment to legal solutions is emblematic of mainstream views of law as a problem-solving instrument. Notwithstanding awareness of its failings, law reformers remain dedicated to using law as a tool for social change. Employing a case study method focusing on the new courthouse, I challenge a prevailing wisdom that law reform outputs are manageable and in our control. I argue that similar to a courthouse, which is a concrete, physical structure as well as a symbol of justice, so too is the legal instrument both material and metaphorical, with concrete outcomes and symbolic forms. While treating law as a literal tool may give law reformers a longed-for sense of mastery, this approach belies law’s diffuse constitutive power and the various paradoxes in reformers’ actions. Accepting law’s dual nature is essential for candid and accurate assessments about the possibilities and limits of change through law.
Use of social media and online dating among individuals with a history of affective disorder
Authors: Rydahl Klara F. K. , Brund René B. K. , Medici Clara R. , Hansen Vibeke , Straarup Krista N. , Straszek Sune P. V. , Østergaard Søren D.
Published: October 2020

Objectives:

To investigate how individuals with a history of affective disorder use and perceive their use of social media and online dating.

Methods:

A questionnaire focusing on affective disorders and the use of social media and online dating was handed out to outpatients from unipolar depression and bipolar disorder clinics and general practice patients with or without a history of affective disorders (latter as controls). The association between affective disorders and use of social media and online dating was analysed using linear/logistic regression.

Results:

A total of 194 individuals with a history of unipolar depression, 124 individuals with a history of bipolar disorder and 196 controls were included in the analysis. Having a history of unipolar depression or bipolar disorder was not associated with the time spent on social media compared with controls. Using the controls as reference, having a history bipolar disorder was associated with use of online dating (adjusted odds ratio: 2.2 (95% CI: 1.3; 3.7)). The use of social media and online dating had a mood-congruent pattern with decreased and more passive use during depressive episodes, and increased and more active use during hypomanic/manic episodes. Among the respondents with a history of affective disorder, 51% reported that social media use had an aggravating effect on symptoms during mood episodes, while 10% reported a beneficial effect. For online dating, the equivalent proportions were 49% (aggravation) and 20% (benefit), respectively.

Conclusion:

The use of social media and online dating seems related to symptom deterioration among individuals with affective disorder.
Fasting and refeeding cycles alter subcutaneous white depot growth dynamics and the morphology of brown adipose tissue in female rats
Authors: Rosas Fernández Mariana , Concha Vilca Carlos , Batista Leandro O. , Figueiredo Letícia S. , Ribeiro Rosane A. , Tavares do Carmo Maria das Graças , Albuquerque Kelse T.
Published: October 2020

Intermittent food restriction (IFR) is used mainly for weight loss; however, its effects on adipose tissue are not known when alternating with an obesogenic diet. To demonstrate its effects on morphological dynamics of fat deposits, female Wistar rats were distributed into groups: standard control (ST-C), with commercial diet; DIO control (DIO-C), with a diet that induces obesity (DIO) during the first and last 15 d, replaced by a standard diet for thirty intermediate days; standard restricted (ST-R), with standard diet during the first and last 15 d, with six cycles of IFR at 50 % of ST-C; and DIO restricted (DIO-R), in DIO during the first and last 15 d, with six cycles of IFR at 50 % of DIO-C. At 105 d of life, white adipose tissue (WAT) and brown adipose tissue (BAT) deposits were collected, weighed and histology performed. The DIO-R group showed higher total food intake (DIO-R 10 768·0 (SEM 357·52) kJ/g v. DIO-C 8868·6 (SEM 249·25) kJ/g, P < 0·0001), energy efficiency during RAI (DIO-R 2·26 (SEM 0·05) g/kJ v. DIO-C 0·70 (SEM 0·03) g/kJ, P < 0·0001) and WAT (DIO-R 5·65 (SEM 0·30) g/100 g v. DIO-C 4·56 (SEM 0·30) g/100 g) than their respective control. Furthermore, IFR groups presented hypertrophy of WAT and BAT, as well as fibrosis in BAT. Thus, IFR can establish prospective resistance to weight loss by favouring changes in adipose tissue morphology, increased energy intake and efficiency. Finally, the DIO diet before and after IFR aggravates the damages caused by the restriction.
Irregular daily energy intake and diet quality in Iranian adults
Authors: Jayedi Ahmad , Lesani Azadeh , Akbarzadeh Zahra , Djafarian Kurosh , Shab-Bidar Sakineh
Published: October 2020

The present cross-sectional study aimed to assess the association of daily irregularity in energy intake and diet quality among apparently healthy adults in Iran. The research was conducted on 850 adult men and women (age range: 20–59 years) who attended health care centres in Tehran. Dietary intake was assessed by three, 24-h dietary recalls. Diet quality was assessed using the Dietary Approaches to Stop Hypertension (DASH) diet score and Healthy Eating Index-2015 (HEI-2015). An irregularity score of daily energy intake was calculated based on the deviation from the 3-d mean energy intake, with a higher score indicating more fluctuations in daily energy intake. Multiple linear regression analysis was used to assess the association of irregularity score of daily energy intake with food group intakes and DASH diet score and HEI-2015, controlling for age, sex, BMI, physical activity, education level and occupation status. The range of irregularity score was 0·55–133·3 (22·4 (sd 19·0)). Higher irregularity score of daily energy intake was significantly associated with a lower consumption of fruit, vegetables, legumes, low-fat dairy products and poultry, higher consumption of soft drinks, processed meat and nuts, and lower overall DASH diet score and HEI-2015. Overall, our findings showed that more day-to-day variations in energy intake may be correlated with a lower diet quality. More research is needed to confirm the associations observed in the present study and to clarify potential mechanisms explaining these associations.
Community engagement in Health Technology Assessment and beyond: from guests in the process to hosts
Authors: Holliday Catherine M.
Published: October 2020

In Health Technology Assessment (HTA), clinical and economic evidence are assessed in the regulatory and reimbursement environments, with community input considered as complementary to this. Stakeholders are calling for more meaningful community engagement, but this will not be reached without a significant shift. The Centre for Community-Driven Research (CCDR) is a nonprofit organization bringing much needed change to the way we think about community engagement in health. This article is based on CCDR's experience and outlines three system changes needed to advance community engagement in decisions about health and HTA. This paper comes from the perspective of engaging everyday people in the process as opposed to representation on panels and committees. The three key areas of change that are discussed include building holistic evidence, creating supportive environments, and infrastructure for community engagement, with the term community referring to people affected by disease or health conditions and their carers/families.
Predictors of mortality among multidrug-resistant tuberculosis patients in central Ethiopia: a retrospective follow-up study
Authors: Kassa Getahun Molla , Tadesse Abilo , Gelaw Yalemzewod Assefa , Alemayehu Temesgen Tadesse , Tsegaye Adino Tesfahun , Tamirat Koku Sisay , Akalu Temesgen Yihunie
Published: October 2020

The burden of multidrug-resistant tuberculosis (MDR-TB) related to mortality in resource-poor countries remains high. This study aimed to estimate the incidence and predictors of death among MDR-TB patients in central Ethiopia. A retrospective follow-up study was conducted at three hospitals in the Amhara region on 451 patients receiving treatment for MDR-TB from September 2010 to January 2017. Data were collected from patient registration books, charts and computer databases. Data were fitted to a parametric frailty model and survival was expressed as an adjusted hazard ratio (AHR) with a 95% confidence interval (CI). The median follow-up time of participants was 20 months (interquartile range: 12, 22) and 46 (10.20%) of patients died during this period. The incidence rate of mortality was 7.42 (95% CI 5.56–9.91)/100 person-years. Older age (AHR = 1.04, 95% CI 1.01–1.08), inability to self-care (AHR = 13.71, 95% CI 5.46–34.40), co-morbidity (AHR = 5.74, 95% CI 2.19–15.08), low body mass index (AHR = 4.13, 95% CI 1.02–16.64), acute lung complications (AHR = 4.22, 95% CI 1.66–10.70) and lung consolidation at baseline (AHR = 5.27, 95% CI 1.06–26.18) were independent predictors of mortality. Most of the identified predictor factors of death in this study were considered to be avoidable if the TB programme had provided nutritional support for malnourished patients and ensured a close follow-up of the elderly, and patients with co-morbidities.
Advances in the study of zygote activation in higher plants
Authors: Li Dong Xiao , Chen Shi Jun , Tian Hui Qiao
Published: October 2020

In higher plants, fertilization induces many structural and physiological changes in the fertilized egg that reflect the transition from the haploid female gamete to the diploid zygote – the first cell of the sporophyte. After fusion of the egg nucleus with the sperm nucleus, many molecular changes occur in the zygote during the process of zygote activation during embryogenesis. The zygote originates from the egg, from which some pre-stored translation initiation factors transfer into the zygote and function during zygote activation. This indicates that the control of zygote activation is pre-set in the egg. After the egg and sperm nuclei fuse, gene expression is activated in the zygote, and paternal and maternal gene expression patterns are displayed. This highlights the diversity of zygotic genome activation in higher plants. In addition to new gene expression in the zygote, some genes show quantitative changes in expression. The asymmetrical division of the zygote produces an apical cell and a basal cell that have different destinies during plant reconstruction; these destinies are determined in the zygote. This review describes significant advances in research on the mechanisms controlling zygote activation in higher plants.
Consumption of multiple micronutrients or small-quantity lipid-based nutrient supplements containing iodine at the recommended dose during pregnancy, compared with iron and folic acid, does not affect women’s urinary iodine concentration in rural Malawi: a secondary outcome analysis of the iLiNS DYAD trial
Authors: Adu-Afarwuah Seth , Arnold Charles D , Maleta Kenneth , Ashorn Per , Ashorn Ulla , Jorgensen Josh M , Fan Yue-Mei , Nkhoma Minyanga , Bendabenda Jaden , Matchado Andrew , Dewey Kathryn G
Published: October 2020

Objectives:

Inadequate iodine intake during pregnancy increases the risk of neonatal morbidity and mortality. We aimed to evaluate whether prenatal supplements containing iodine affect urinary iodine concentrations (UIC) of pregnant women in Malawi.

Design:

A randomised controlled trial. Pregnant women (n 1391) were assigned to consume 60 mg/d Fe and 400 µg/d folic acid (IFA) or 18 vitamins and minerals including 250 µg/d iodine (MMN) or 20 g/d small-quantity lipid-based nutrient supplements (SQ-LNS) with similar nutrient contents as MMN group, plus macronutrients (LNS) until childbirth. In a sub-study (n 317), we evaluated group geometric mean urinary iodine concentration (UIC) (µg/L) at 36 weeks of gestation controlling for baseline UIC and compared median (baseline) and geometric mean (36 weeks) UIC with WHO cut-offs: UIC < 150, 150–249, 250–499 and ≥500 reflecting insufficient, adequate, above requirements and excessive iodine intakes, respectively.

Setting:

Mangochi District, Malawi.

Participants:

Women ≤20 weeks pregnant.

Results:

Groups had comparable background characteristics. At baseline, overall median (Q1, Q3) UIC (319 (167, 559)) suggested iodine intakes above requirements. At 36 weeks, the geometric mean (95 % CI) UIC of the IFA (197 (171, 226)), MMN (212 (185, 243)) and LNS (220 (192, 253)) groups did not differ (P = 0·53) and reflected adequate intakes.

Conclusions:

In this setting, provision of supplements containing iodine at the recommended dose to pregnant women with relatively high iodine intakes at baseline, presumably from iodised salt, has no impact on the women’s UIC. Regular monitoring of the iodine status of pregnant women in such settings is advisable. Clinicaltrials.gov identifier: NCT01239693.
Double burden of malnutrition and its association with infant and young child feeding practices among children under-five in Thailand
Authors: Benedict Leshawn , Hong Seo Ah , Winichagoon Pattanee , Tejativaddhana Phudit , Kasemsup Vijj
Published: October 2020

Objective:

This study examined the prevalence of stunting-overweight and socio-demographic determinants among children under-five years of age, as well as associations with infant and young child feeding (IYCF) among children aged 6–23 months.

Design:

Secondary data analysis based on the Thailand Multiple Indicator Cluster Survey 2015–2016.

Setting:

Cross-national study.

Participants:

Nationally representative sample of children under-five years of age (n 12 313).

Results:

The prevalence of wasting, stunting, overweight and stunting-overweight was 5·3, 10·5, 10·1 and 1·6 %, respectively. In multivariate analyses, children under 6 months, children from low and middle wealth tertiles, and children living in rural areas were prone to being wasted. Male children, low wealth tertile and a non-Thai speaking household head were positively and children aged 48–59 months and a one-child household were inversely associated with stunting. Children from a low wealth tertile were less likely to be overweight, while older age, male children and children from a one-child household were more likely to be overweight. Stunting-overweight was associated with children aged 24–47 months, male children, mothers having secondary education, a one-child household, a non-Thai speaking household head and an urban area. In terms of IYCF indicators, despite no association with stunting and stunted-overweight children, current breast-feeding and inadequate meal frequency were associated with being wasting, while current breast-feeding and dietary diversity were inversely associated with being overweight.

Conclusions:

This study revealed the double burden of malnutrition at the individual and population levels among Thai children under-five, which calls for concrete integrated interventions to tackle all forms of malnutrition.
High BMI: an important health risk factor among older adults in Ghana
Authors: Yorke E , Tetteh J , Boima Vincent , Yawson AE
Published: October 2020

Objective:

We examined BMI as a health risk factor for self-reported diabetes mellitus, angina, strokes and arthritis among older Ghanaians aged 50 years and above.

Design:

We analysed the individual-level data from the World Health Organization Study on global AGEing and adult health Ghana Wave 2 (2014/2015). The influence of BMI on self-reported chronic conditions including diabetes, angina, stroke and arthritis was examined.

Setting:

Households from all the administrative regions of Ghana.

Participants:

Included 3350 adults aged 50 years and older.

Results:

The prevalence of overweight and obesity among participants was 22·8 % (95 % CI 20·6, 25·2) and 13·2 %, respectively (95 % CI 11·5, 15·1). With respect to individual chronic conditions, arthritis emerged with the highest prevalence rate of 7·3 (95 % CI 5·3, 9·9), while the prevalence rate of diabetes, angina and stroke was 2·8 % (95 % CI 2·0, 3·9), 1·7 % (95 % CI 1·1, 2·6) and 1·3 % (95 % CI 1·0, 1·8), respectively. The risk of diabetes among overweight and obesity was over three and two times, respectively, higher compared with participants with normal weights. Overweight and obesity were significantly more than two and three times likely to experience angina, respectively, compared with participants with normal weight. Obesity significantly influences arthritis with approximately two times increased odds compared with normal weight participants.

Conclusion:

Prevalence of obesity and overweight in Ghana is high and increasing, which poses a health risk at the individual and population levels. Inter-sectorial and multidisciplinary measures in line with the national non-communicable disease policies aimed at curbing this trend are imperative.
Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and RapidArc in low grade mucoepidermoid carcinoma of the salivary gland: a single institutional experience
Authors: Ghaffar Amna , Yousaf Muhammad , Anees Minhas Sajid , Hameed Rizwan , Zafar Umair , Iqbal Khalid
Published: October 2020

Purpose:

To report a single-institution experience of intensity-modulated radiotherapy (IMRT) and RapidArc treatment plans for the patients treated with low grade mucoepidermoid carcinoma (MEC) of the salivary gland while sparing the organs at risk (OARs) within tolerance limits.

Material and Methods:

Twenty-five patients with MEC were selected to develop and analyse the treatment plans using both of the techniques. Dose distributions were calculated using Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA). Plans were generated to deliver the dose of 6000 cGy in 30 fractions. For IMRT, seven angle plans were used and for RapidArc, two half arcs were used with the same 6 MV photon beam. Quality of treatment plans was evaluated by using parameters such as, coverage, conformity index (CI), homogeneity index (HI), gradient index (GI), unified dosimetry index (UDI), dose volume histogram, delivery time and OARs sparing for IMRT and RapidArc plans.

Results:

The analysis revealed that IMRT and RapidArc coverages are 0·90 and 0·94, respectively; CIs are 1·15 and 1·10, respectively; HIs are 1·12 and 1·07, respectively; GIs are 0·94 and 0·98, respectively. Average UDI values for RapidArc and IMRT are 1·09 and 1·11, respectively. Integral dose comparison shows better OAR sparing for RapidArc. RapidArc plans have the shorter beam on time (45%) in comparison with IMRT plans.

Conclusion:

Planning constraints were achieved in both techniques. However, RapidArc showed better quality treatment plan, OARs sparing and shorter delivery time as compared to IMRT.
Redistribution in collective pension arrangements without a sponsor guarantee: Hidden versus explicit risk transactions
Authors: Yi Lu , Sanders Barbara , Bégin Jean-François
Published: October 2020

In collective pension arrangements without a sponsor guarantee, assets and liabilities are commingled, and members' benefits are adjusted to reflect emerging plan experience. Stakeholders pay attention to the fairness of the intergenerational transactions arising from the inclusion of certain design elements; however, implicit intergenerational transactions exist even in pure collective defined contribution (CDC) arrangements without any such explicit stabilization mechanisms. In this study, we find that the implicit risk transactions are uneven: significant value transfers among cohorts can result from joining a pure CDC plan. We then compare these to the additional value transfers arising from explicit stabilization mechanisms.
Das Herzgeräusch als Zufallsbefund
Authors: Frey Simon M. , Zellweger Michael J.
Published: October 2020

Zusammenfassung. Herzgeräusche (HG) sind sehr häufig und treten in bis zu 80 % der Schulkinder und 52 % der Erwachsenen auf. Sie entstehen durch den Wechsel von laminarem zu turbulentem Fluss und können im Rahmen einer strukturellen Kardiopathie (als sogenannte «organische» HG) oder bei Herzgesunden (als sogenannte «harmlose» HG) auftreten. Eine detaillierte Anamnese und körperliche Untersuchung helfen bei der Unterscheidung. Die Auskultation hat wegen der breiten Verfügbarkeit der Echokardiographie an Bedeutung verloren, ist jedoch zur initialen Beurteilung und Triagierung weiterhin wichtig. Ein harmloses Herzgeräusch ist ein leises (1 / 6 – 2 / 6), crescendo-decrescendo, meistens lageabhängiges, mitt-systolisches Systolikum ohne Ausstrahlung, welches bei asymptomatischen Patienten mit normaler Leistungsfähigkeit nicht weiter abklärungsbedürftig ist. Bestehen in der Anamnese, im Status oder anderen durchgeführten Untersuchungen Hinweise auf eine kardiale Erkrankung sollte niederschwellig eine transthorakale Echokardiographie erfolgen. Diastolika und kontinuierliche Herzgeräusche sind in der Regel pathologisch und bedürfen einer weiteren Abklärung.
Thrombozytopenie als Zufallsbefund
Authors: Holbro Andreas , Passweg Jakob R.
Published: October 2020

Zusammenfassung. Thrombozyten spielen eine wichtige Rolle unter anderem für eine normale Hämostase. Ihre Zahl ist relativ konstant und eine Verminderung der Thrombozytenzahl (eine Thrombozytopenie) ist ein häufiger Befund. Als erstes sollte man eine sogenannte Pseudothrombozytopenie ausschliessen. Die weitere Abklärung hängt von der Klinik ab. Beim blutenden Patienten muss man unmittelbar handeln. Als erster Schritt sollte ein handdifferenziertes Blutbild veranlasst werden. Aufgrund der breiten Differenzialdiagnose sollte man bei der weiteren Abklärung schrittweise vorgehen und den Hämatologen involvieren. Eine klare Diagnose ist essenziell, vor allem um bei Bedarf (Blutungen, geplante operative Eingriffe, zusätzliche Einnahme von Aggregationshemmern und / oder Antikoagulanzien) die korrekten therapeutischen Massnahmen und Interventionen einzuleiten.
Methane and Carbon Dioxide Emissions From Reservoirs: Controls and Upscaling
Authors: Beaulieu Jake J. , Waldo Sarah , Balz David A. , Barnett Will , Hall Alexander , Platz Michelle C. , White Karen M.
Published: October 2020

Estimating carbon dioxide (CO2) and methane (CH4) emission rates from reservoirs is important for regional and national greenhouse gas inventories. A lack of methodologically consistent data sets for many parts of the world, including agriculturally intensive areas of the United States, poses a major challenge to the development of models for predicting emission rates. In this study, we used a systematic approach to measure CO2 and CH4 diffusive and ebullitive emission rates from 32 reservoirs distributed across an agricultural to forested land use gradient in the United States. We found that all reservoirs were a source of CH4 to the atmosphere, with ebullition being the dominant emission pathway in 75% of the systems. Ebullition was a negligible emission pathway for CO2, and 65% of sampled reservoirs were a net CO2 sink. Boosted regression trees (BRTs), a type of machine learning algorithm, identified reservoir morphology and watershed agricultural land use as important predictors of emission rates. We used the BRT to predict CH4 emission rates for reservoirs in the U.S. state of Ohio and estimate they are the fourth largest anthropogenic CH4 source in the state. Our work demonstrates that CH4 emission rates for reservoirs in our study region can be predicted from information in readily available national geodatabases. Expanded sampling campaigns could generate the data needed to train models for upscaling in other U.S. regions or nationally.
Reducing Uncertainties of Future Global Soil Carbon Responses to Climate and Land Use Change With Emergent Constraints
Authors: Xu Wenfang , Chang Jinfeng , Ciais Philippe , Guenet Bertrand , Viovy Nicolas , Ito Akihiko , Reyer Christopher P. O. , Tian Hanqin , Shi Hao , Frieler Katja , Forrest Matthew , Ostberg Sebastian , Schaphoff Sibyll , Hickler Thomas
Published: October 2020

Soil organic carbon changes (ΔSOC) are regulated by climate and land use change. Here, we analyze regional and global ΔSOC from 1861 to 2099 based on five terrestrial biosphere model (TBM) simulations of the Inter‐Sectoral Impact Model Intercomparison Project Phase 2b. The TBMs were driven by harmonized gridded land use change and bias‐adjusted climate forcing data from different general circulation models (GCMs) for climate scenarios RCP 2.6 and RCP 6.0. Between 2005 and the end of this century, we estimated an increase of SOC for two scenarios with large uncertainty, which is dominated by differences between TBMs. We present a new emergent constraint approach to constrain future modeled ΔSOC over natural vegetation from RCP 6.0 simulations using recent observed trends of net primary productivity as a proxy of litter inputs to soil pools. Our results showed that the uncertainties in constrained ΔSOC can be reduced in comparison with the original model ensemble, but constrained values of ΔSOC depend on the choice of a GCM and climate regions. For the reduction of the SOC density in areas where cropland expanded (Δsoccropland expansion) over natural vegetation as a result of land use change, the constrained Δsoccropland expansion still features large uncertainties due to uncertain observed data. Our proposed emergent constraint approach appears to be valuable to reduce uncertainty on SOC projections, but it is limited here by the small number of models (five) and by the uncertainty in the observational data. Applications to larger ensembles from Earth System Models should be tested for the future.
Impacts of Ocean Wave‐Dependent Momentum Flux on Global Ocean Climate
Authors: Shimura Tomoya , Hemer Mark , Lenton Andrew , Chamberlain Matthew A. , Monselesan Didier
Published: October 2020

Accurate knowledge of air‐sea fluxes of momentum, heat, and carbon are central to fully understanding the evolution of the climate system. The role of ocean surface waves has been largely overlooked in global climate models despite the growing body of work elucidating the influence of ocean wave state on air‐sea fluxes. Here we account for the impact of ocean surface waves on global ocean climate using a global ocean model through implementation of wave‐dependent momentum fluxes. Wave‐dependent momentum fluxes improve the simulation of observed ocean heat content (OHC) through increasing the trend in OHC over the last three decades. Specifically, the larger increase in OHC is attributable to increased net heat flux in the Southern Hemisphere (SH). These results highlight the important role of accounting for wave‐dependent momentum transfer in terms of both simulating future climate and understanding changes over the recent historical period.
First Direct Observations of Propagation of Discrete Chorus Elements From the Equatorial Source to Higher Latitudes, Using the Van Allen Probes and Arase Satellites
Authors: Colpitts Chris , Miyoshi Yoshizumi , Kasahara Yoshiya , Delzanno Gian Luca , Wygant John R. , Cattell Cynthia A. , Breneman Aaron , Kletzing Craig , Cunningham Greg , Hikishima Mitsuru , Matsuda Shoya , Katoh Yuto , Ripoll Jean‐Francois , Shinohara Iku , Matsuoka Ayako
Published: October 2020

Whistler mode chorus waves have recently been established as the most likely candidate for scattering relativistic electrons to produce the electron microbursts observed by low altitude satellites and balloons. These waves would have to propagate from the equatorial source region to significantly higher magnetic latitude in order to scatter electrons of these relativistic energies. This theoretically proposed propagation has never been directly observed. We present the first direct observations of the same discrete rising tone chorus elements propagating from a near equatorial (Van Allen Probes) to an off‐equatorial (Arase) satellite. The chorus is observed first on the more equatorial satellite and is found to be more oblique and significantly attenuated at the off‐equatorial satellite. This is consistent with the prevailing theory of chorus propagation and with the idea that chorus must propagate from the equatorial source region to higher latitudes. Ray tracing of chorus at the observed frequencies confirms that these elements could be generated parallel to the field at the equator, and propagate through the medium unducted to Van Allen Probes A and then to Arase with the observed time delay, and have the observed obliquity and intensity at each satellite.
The Complicated Link Between Material Properties and Microfracture Density for an Underground Explosion in Granite
Authors: Swanson E. , Wilson J. , Broome S. , Sussman A.
Published: October 2020

Geophysical techniques are often implemented as quick and inexpensive ways to locate and characterize fractures in the subsurface, which is important for a number of geoscience fields. Seismic velocities are the most widely used proxies for identification of fractures, but the correlation is not always well defined. Here we present material property data: unconfined compressive strength, bulk density (ρ), Young's modulus (E), Poisson's ratio (ν), P wave velocity (Vp), and S wave velocity (Vs), in conjunction with microfracture densities measured on samples of granite collected before and after underground chemical explosions. Results indicate the relationship between fractures and material properties is complex, even in this single‐lithology environment. We interpret that this complexity arises from varying fracture mechanisms (e.g., dilation‐inducing fractures vs. compression‐inducing fractures) in different parts of the core, due to differences in stress conditions. Additional complexity may result from chemical interactions between the fresh fractures and the fluids in the area. Water content appears to have a significant, if not dominant, role in the unconfined compressive strength of the samples. We suggest caution when using elastic property measurements as a proxy for fracturing in areas of explosion‐induced damage, or in other areas where a variety of mechanisms induce fracturing.
Investigation of Isoprene Dynamics During the Day‐to‐Night Transition Period
Authors: Wei Dandan , Alwe Hariprasad D. , Millet Dylan B. , Kavassalis Sarah C. , Lew Michelle , Bottorff Brandon , Stevens Philip S. , Steiner Allison L.
Published: October 2020

At the University of Michigan Biological Station during the 2016 AMOS field campaign, isoprene concentrations typically peak in the early afternoon (around 15:00 local time, LT) under well‐mixed conditions. However, an end‐of‐day peak (around 21:00 LT) occurs on 23% of the campaign days, followed by a rapid removal (from 21:00–22:00 LT) at rate of 0.57 hr−1 during the day‐to‐night transition period. During the end‐of‐day peak, in‐canopy isoprene concentrations increase by 77% (from 3.5 to 6.2 ppbv) on average. Stratification and weak winds (<3.4 m s−1 at 46 m) significantly suppress turbulent exchanges between in‐ and above‐canopy, leading to accumulation of isoprene emitted at dusk. A critical standard deviation of the vertical velocity (σw) of 0.14, 0.2, and 0.29 m s−1 is identified to detect the end‐of‐day peak for the height of 13, 21, and 34 m, respectively. In 85% of the end‐of‐day cases, the wind speed increases above 2.5 m s−1 after the peak along with a shift in wind direction, and turbulence is reestablished. Therefore, the wind speed of 2.5 m s−1 is considered as the threshold point where turbulence switches from being independent of wind speed to dependent on wind speed. The reinstated turbulence accounts for 80% of the subsequent isoprene removal with the remaining 20% explained by chemical reactions with hydroxyl radicals, ozone, and nitrate radicals. Observed isoprene fluxes do not support the argument that the end‐of‐day peak is reduced by vertical turbulent mixing, and we hypothesize that horizontal advection may play a role.
Comment on “Unraveling the Mystery of Indian Summer Monsoon Prediction: Improved Estimate of Predictability Limit” by Saha et al.
Authors: Swenson Erik T. , Das Debanjana , Shukla J.
Published: October 2020

In a recent study, Saha et al. (2019, https://doi.org/10.1029/2018JD030082) examine the correlation between boreal summer seasonal mean rainfall over India and rainfall variance as a function of subseasonal time scale and find that the correlation has a local maximum (exceeding a value of 0.6) for synoptic time scales (2–5 day periods). They claim these results to be a major advancement in understanding monsoon predictability but do not provide a clear physical explanation. Here we examine the sensitivity of this relationship to the details of the analysis and only consider the observed correlation identified by Saha et al. (2019, https://doi.org/10.1029/2018JD030082). There is large sensitivity in the correlation maximum between spatially averaged seasonal mean rainfall and synoptic scale rainfall variance averaged over the same domain. The correlation maximum is weaker over the longer period of 1901–2015, and more notably it is highly sensitive to the domain of prior averaging. A correlation peak is not found outside central India and is neither found within central India when averaging over a smaller domain. Averaging over a larger domain results in a disproportionate reduction in synoptic variance (that is of most interest). The peak in correlation between seasonal mean and 2–5 day variance only emerges after first averaging over a sufficiently large region; thus, the maximum appears to be an artifact of spatial averaging. It is further pointed out that a positive mean‐variance relationship is an intrinsic property of rainfall, and thus, its existence alone does not necessarily imply any physical, causal, and/or predictive connection between time scales.
Special Classes of Terrestrial Gamma Ray Flashes From RHESSI
Authors: Smith D. M. , Kelley N. A. , Buzbee P. , Infanger A. , Splitt M. , Holzworth R. H. , Dwyer J. R.
Published: October 2020

We report on three classes of terrestrial gamma ray flashes (TGFs) from the (RHESSI) satellite. The first class drives the detectors into paralysis, being observed usually through a few counts on the rising edge and the later tail of Comptonized photons. These events—and any bright TGF—reveal their true luminosity more clearly via their Compton tail than via the main peak, since the former is unaffected by the unknown beaming pattern of the unscattered radiation, and Comptonization mostly isotropizes the flux. This technique could be applied to TGFs from any mission. The second class is more than usually bright and long in duration. When the magnetic field at the conjugate point is stronger than at the nearby footpoint, we find that 4 out of 11 such events show a significant signal at the time expected for a relativistic electron beam to make a round trip to the opposite footpoint and back. We conclude that a large fraction of TGFs lasting more than a few hundred microseconds may include counts due to the upward moving secondary particle beam ejected from the atmosphere. Finally, using a new search algorithm to find short TGFs in RHESSI, we see that these tend to occur more often over the oceans than land, relative to longer‐duration events. In the feedback model of TGF production, this suggests a higher thunderstorm potential, since more feedback per avalanche implies fewer “generations” of avalanches needed to complete the TGF discharge.
Ejection of Dust From the Ocean as a Potential Source of Marine Ice Nucleating Particles
Authors: Cornwell Gavin C. , Sultana Camille M. , Prank Marje , Cochran Richard E. , Hill Thomas C. J. , Schill Gregory P. , DeMott Paul J. , Mahowald Natalie , Prather Kimberly A.
Published: October 2020

Oceans are, generally, relatively weak sources of ice nucleating particles (INPs). Thus, dust transported from terrestrial regions can dominate atmospheric INP concentrations even in remote marine regions. Studies of ocean‐emitted INPs have focused upon sea spray aerosols containing biogenic species. Even though large concentrations of dust are transported over marine regions, resuspended dust has never been explicitly considered as another possible source of ocean‐emitted INPs. Current models assume that deposited dust is not re‐emitted from surface waters. Our laboratory studies of aerosol particles produced from coastal seawater and synthetic seawater doped with dust show that dust can indeed be ejected from water during bubble bursting. INP concentration measurements show these ejected dust particles retain ice nucleating activity. Doping synthetic seawater to simulate a strong dust deposition event produced INPs active at temperatures colder than −13°C and INP concentrations 1 to 2 orders of magnitude greater than either lab sea spray or marine boundary layer measurements. The relevance of these laboratory findings is highlighted by single‐particle composition measurements along the Californian coast where at least 9% of dust particles were mixed with sea salt. Additionally, global modeling studies show that resuspension of dust from the ocean could exert the most impact over the Southern Ocean, where ocean‐emitted INPs are thought to dominate atmospheric INP populations. More work characterizing the factors governing the resuspension of dust particles is required to understand the potential impact upon clouds.
How Well Do Large‐Eddy Simulations and Global Climate Models Represent Observed Boundary Layer Structures and Low Clouds Over the Summertime Southern Ocean?
Authors: Atlas R. L. , Bretherton C. S. , Blossey P. N. , Gettelman A. , Bardeen C. , Lin Pu , Ming Yi
Published: October 2020

Climate models struggle to accurately represent the highly reflective boundary layer clouds overlying the remote and stormy Southern Ocean. We use in situ aircraft observations from the Southern Ocean Clouds, Radiation and Aerosol Transport Experimental Study (SOCRATES) to evaluate Southern Ocean clouds in a cloud‐resolving large‐eddy simulation (LES) and two coarse resolution global atmospheric models, the CESM Community Atmosphere Model (CAM6) and the GFDL Atmosphere Model (AM4), run in a nudged hindcast framework. We develop six case studies from SOCRATES data which span the range of observed cloud and boundary layer properties. For each case, the LES is run once forced purely using reanalysis data (fifth generation European Centre for Medium‐Range Weather Forecasts atmospheric reanalysis, “ERA5 based”) and once strongly nudged to an aircraft profile(“Obs based”). The ERA5‐based LES can be compared with the global models, which are also nudged to reanalysis data and are better for simulating cumulus. The Obs‐based LES closely matches an observed cloud profile and is useful for microphysical comparisons and sensitivity tests and simulating multilayer stratiform clouds. We use two‐moment Morrison microphysics in the LES and find that it simulates too few frozen particles in clouds occurring within the Hallett‐Mossop temperature range. We tweak the Hallett‐Mossop parameterization so that it activates within boundary layer clouds, and we achieve better agreement between observed and simulated microphysics. The nudged global climate models (GCMs) simulate liquid‐dominated mixed‐phase clouds in the stratiform cases but excessively glaciate cumulus clouds. Both GCMs struggle to represent two‐layer clouds, and CAM6 has low droplet concentrations in all cases and underpredicts stratiform cloud‐driven turbulence.
Probabilistic Forecasts of Storm Sudden Commencements From Interplanetary Shocks Using Machine Learning
Authors: Smith A. W. , Rae I. J. , Forsyth C. , Oliveira D. M. , Freeman M. P. , Jackson D. R.
Published: October 2020

In this study we investigate the ability of several different machine learning models to provide probabilistic predictions as to whether interplanetary shocks observed upstream of the Earth at L1 will lead to immediate (Sudden Commencements, SCs) or longer lasting magnetospheric activity (Storm Sudden Commencements, SSCs). Four models are tested including linear (Logistic Regression), nonlinear (Naive Bayes and Gaussian Process), and ensemble (Random Forest) models and are shown to provide skillful and reliable forecasts of SCs with Brier Skill Scores (BSSs) of ∼0.3 and ROC scores >0.8. The most powerful predictive parameter is found to be the range in the interplanetary magnetic field. The models also produce skillful forecasts of SSCs, though with less reliability than was found for SCs. The BSSs and ROC scores returned are ∼0.21 and 0.82, respectively. The most important parameter for these predictions was found to be the minimum observed BZ. The simple parameterization of the shock was tested by including additional features related to magnetospheric indices and their changes during shock impact, resulting in moderate increases in reliability. Several parameters, such as velocity and density, may be able to be more accurately predicted at a longer lead time, for example, from heliospheric imagery. When the input was limited to the velocity and density the models were found to perform well at forecasting SSCs, though with lower reliability than previously (BSSs ∼ 0.16, ROC Scores ∼ 0.8), Finally, the models were tested with hypothetical extreme data beyond current observations, showing dramatically different extrapolations.