bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron Deficiency and the Brain
Authors: PARKS Y. A. , WHARTON B. A.
Published: February 2018

Parks, Y. A. and Wharton, B. A. (Community Health and Mental Handicap Services, Canterbury; University of Glasgow, Department of Human Nutrition, Glasgow, UK). Iron deficiency and the brain.

There is increasing evidence both from ‘association’ and ‘intervention’ studies that iron deficiency has an adverse effect on brain function In animals and children. The severity and duration of iron deficiency are important in determining the effect on development. Iron replacement therapy has immediate (within 14 days) and long‐term (over 3 months) beneficial effects on behaviour and psychomotor development. The mechanisms for this probably involve a number of biochemical pathways in which iron is essential. These include mitochondrial enzymes and various neurotransmitters. Cytochrome C is reduced by iron deficiency but brain tissue is relatively spared until the deficiency is severe. Levels of neurotransmitters such as noradrenaline, serotonin and dopamine are all altered during iron deficiency and this may explain some of the behavioural and developmental changes that occur.
Impact of Increased Growth Hormone Secretion on Carbohydrate Metabolism in Adolescents with Diabetes
Authors: DUNGER D.B. , EDGE J.A. , PAL R. , TAYLOR A.M. , HOLLY J.M.P. , MATTHEWS D.R.
Published: February 2018

Growth hormone (GH) and fasting insulin concentrations rise during puberty in normal subjects. Any increase in GH secretion in adolescents with insulin‐dependent diabetes mellitus (IDDM) might be expected to lead to further insulin resistance and metabolic disturbance. Despite the high incidence of delayed growth in IDDM, the relationship between Gli, insulin‐like growth factor I (IGF‐I) and IGF binding protein 1 (IGFBP‐1) has not been clearly established. Twenty‐six adolescents with IDDM and 34 healthy siblings underwent measurement of their overnight GH secretory profiles (20.00–08.00 hours, 15‐minute sampling). The diabetic subjects were studied either on their normal insulin regimen (n = 15) or during a euglycaemic clamp (n = 26). A second clamp study was undertaken (n = 7) with addition of pirenzepine to suppress GH secretion. GH profiles in the diabetic subjects were characterized by increases in both pulse amplitude and baseline GH concentrations . Deconvolution analysis also revealed an increase in the frequency of Gil secretory episodes. In the subjects with diabetes, a direct link between the dawn rise in insulin requirements, increased concentrations of 9‐hydroxybutyrate and the elevated concentrations of GH was established. These abnormalities were reversed by the suppression of GH pulse amplitude following pirenzepine. Serum IGF‐I concentrations and IGF‐I bioactivity in the diabetic subjects were low and were positively correlated with mean GH concentrations. In conclusion, well controlled adolescents with IDDM show persisting abnormalities of GH,β‐hydroxybutyrate and IGF‐I despite normoglycaemia. The role of inappropriate insulin delivery in the development of these abnormalities is discussed.
Regulation of Growth Hormone Secretion in Patients with Growth Hormone Insensitivity
Authors: COTTERILL A.M. , HOLLY J.M.P. , SNODGRASS G.A.I. , SAVAGE M.O.
Published: February 2018

Two subjects with growth hormone (GH) insensitivity were studied using standard methods of examining GH regulation: overnight GH sampling, stimulation of GH secretion with two sequential intravenous injections of GH‐releasing hormone (GHRH), and suppression with somatostatin. Subject 1 was a girl, aged 14 years (height, 103 cm; −8.3 SDS for chronological age). Subject 2 was a boy, aged 11.5 years (height, 103.6 cm; −5.9 SDS for chronological age). The overnight pattern of GH secretion was similar in both subjects and appeared pulsatile with three pulses overnight, the major peaks of 203 mU/l and 206 mU/l in subjects 1 and 2 occurring at 00.00 hours and 00.20 hours, respectively. Serum Gil levels were detectable throughout and the mean overnight serum GH levels were 65 mU/l and 53 mU/l for subjects 1 and 2 respectively. The pattern of GH response to GHRH stimulation was similar in both subjects, with a large rise in GH after the first injection, to a peak of 512 mU/l and 216 mU/l in subjects 1 and 2 respectively. The response to the second GHRH injection was less than the first, with peaks of 486 mU/l and 150 mU/l. During somatostatin infusion, GH levels fell to 7 mU/l and were undetectable in the two subjects respectively, with a rebound following the cessation of infusion. High resolution computerized tomography (CT) scans of both subjects confirmed normal anatomy of the hypothalamus and pituitary with a small gland at the base of the fossa. In conclusion, GH secretion in GH insensitivity is pulsatile and the pituitary is responsive to exogenous GHRH and somatostatin. This suggests that GH feedback does not influence the dual control of the pulsatile release of GH by GHRH and somatostatin, but that GH feedback is necessary for the control of the absolute amounts of GH released during each pulse.
Altered frontal‐amygdala effective connectivity during effortful emotion regulation in bipolar disorder
Authors: Zhang Liwen , Opmeer Esther M , van der Meer Lisette , Aleman André , Ćurčić‐Blake Branislava , Ruhé Henricus G
Published: February 2018

Objectives

Sufficient prefrontal top‐down control of limbic affective areas, especially the amygdala, is essential for successful effortful emotion regulation (ER). Difficulties in effortful ER have been seen in patients with bipolar disorder (BD), which could be suggestive of a disturbed prefrontal‐amygdala regulation circuit. The aim of this study was to investigate whether BD patients show abnormal effective connectivity from the prefrontal areas to the amygdala during effortful ER (reappraisal).

Methods

Forty participants (23 BD patients and 17 healthy controls [HC]) performed an ER task during functional magnetic resonance imaging. Using dynamic causal modeling, we investigated effective connectivity from the dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) to the amygdala, as well as connectivity between the DLPFC and VLPFC during reappraisal.

Results

Both BD patients and HC showed decreased negative affect ratings following reappraisal compared to attending negative pictures (P < .001). There were no group differences (P = .10). There was a differential modulatory effect of reappraisal on the connectivity from the DLPFC to amygdala between BD patients and HC (P = .04), with BD patients showing a weaker modulatory effect on this connectivity compared to HC. There were no other group differences.

Conclusion

The disturbance in BD patients in effective connectivity from the DLPFC to the amygdala while reappraising is indicative of insufficient prefrontal control. This impairment should be studied further in relation to cycling frequency and polarity of switches in BD patients.
Trogocytosis of ligand–receptor complex and its intracellular transport in CD30 signalling
Authors: Nakashima Makoto , Watanabe Mariko , Uchimaru Kaoru , Horie Ryouichi
Published: February 2018

Background Information

CD30, which is characteristically expressed in classical Hodgkin lymphoma (cHL), is thought to transduce signals by ligation of trimerised CD30 ligand (CD30L) on the surface of surrounding cells and recruitment of downstream molecules. In this report, we propose a new mechanism for CD30 signalling by its ligand. We prepared two stable transformants, CHO cells expressing CD30L fused to mCherry and HeLa cells expressing CD30 fused to GFP.

Results

Co‐culture of these cells triggered clustering of CD30 and CD30L at the cellular interface, formation of multiple CD30L–CD30 complexes, internalisation of these complexes with a portion of the plasma membrane into the HeLa cells, and intracellular transport to the lysosomal compartment. The internalisation process was significantly inhibited by actin polymerisation inhibitors. The CD30L–CD30 interaction was found to trigger active signalling processes, as measured by Ca2+ influx, and similar mechanisms were observed using cHL cell lines.

Conclusions

These results suggest that CD30 extracts CD30L from CD30L‐expressing cells by actin‐mediated trogocytosis, resulting in the generation of signalosomes, intracellular signalling, lysosomal degradation and a subsequent refractory phase. We postulate that similar processes may operate in tumours endogenously expressing CD30. These observations thus provide new insights into our understanding of the biological roles of CD30 in normal and malignant cells and, in particular, in cHL.

Significance

This study suggests a novel model of CD30 signalling that provides new insights into the biological roles of CD30 and other members of this family in normal and malignant cells.
The Hilina Pali palaeomagnetic excursion and possible self‐reversal in the loess from western Ukraine
Authors: Nawrocki Jerzy , Bogucki Andriy , Łanczont Maria , Werner Tomasz , Standzikowski Karol , Pańczyk Magdalena
Published: February 2018

A loess‐palaeosol succession from the last glacial cycle was palaeomagnetically studied in the Rivne abandoned brickyard (western Ukraine). Two samples of undisturbed loess from the same depth of parallel sections display steep negative inclinations. These reversed directions in the loess dated at c. 18 ka may possibly be correlated with the Hilina Pali palaeomagnetic excursion. This is the first occurrence of the Hilina Pali in a loess sediment. Unfortunately, the loess with negative inclination does not form any continuous layer that could be suitable for studies of detailed features of geomagnetic field inversion. Another six samples from an illuvial horizon of the Holocene soil also showed negative inclinations and strongly deviated declinations. This part of the section does not represent, however, any palaeomagnetic excursion. The anomalous magnetization in maghemite‐ and titanomagnetite‐rich sediment results most probably from self‐reversal remagnetization. A new insight into palaeomagnetic excursions noted in loess, especially in its parts affected by pedogenic processes, is recommended.
A quarter of patients with type 1 diabetes have co-existing non-islet autoimmunity: the findings of a UK population-based family study
Authors: Kozhakhmetova A , Wyatt R C , Caygill C , Williams C , Long A E , Chandler K , Aitken R J , Wenzlau J M , Davidson H W , Gillespie K M , Williams A J K
Published: February 2018

Individuals with type 1 diabetes (T1D) are at increased risk of coeliac disease (CD), autoimmune thyroiditis and autoimmune gastritis, but the absolute risks are unclear. The aim of this study was to investigate the prevalence of autoantibodies to tissue transglutaminase (TGA), thyroid peroxidase (TPOA) and gastric H+/K+-ATPase (ATPA) and their genetic associations in a well-characterized population-based cohort of individuals with T1D from the Bart's–Oxford family study for whom islet autoantibody prevalence data were already available. Autoantibodies in sera from 1072 patients (males/females 604/468; median age 11·8 years, median T1D duration 2·7 months) were measured by radioimmunoassays; HLA class II risk genotype was analysed in 973 (91%) using polymerase chain reaction with sequence specific primers (PCR-SSP). The prevalence of TGA (and/or history of CD), TPOA and ATPA in patients was 9·0, 9·6 and 8·2%, respectively; 3·1% had two or more autoantibodies. Females were at higher risk of multiple autoimmunity; TGA/CD were associated with younger age and TPOA with older age. ATPA were uncommon in patients under 5 years, and more common in older patients. Anti-glutamate decarboxylase autoantibodies were predictive of co-existing TPOA/ATPA. TGA/CD were associated with human leucocyte antigen (HLA) DR3-DQ2, with the DR3-DQ2/DR3-DQ2 genotype conferring the highest risk, followed by DR4-DQ8/DR4-DQ8. ATPA were associated with DR3-DQ2, DRB1*0404 (in males) and the DR3-DQ2/DR4-DQ8 genotype. TPOA were associated with the DR3-DQ2/DR3-DQ2 genotype. Almost one-quarter of patients diagnosed with T1D aged under 21 years have at least one other organ-specific autoantibody. HLA class II genetic profiling may be useful in identifying those at risk of multiple autoimmunity.
Racial disparities in kidney transplant waitlist appearance in Chicago: Is it race or place?
Authors: Peng Robert B. , Lee Haena , Ke Zheng T. , Saunders Milda R.
Published: February 2018

Background

Prior work has demonstrated how neighborhood poverty and racial composition impact racial disparities in access to the deceased donor kidney transplant waitlist, both nationally and regionally. We examined the association between neighborhood characteristics and racial disparities in time to transplant waitlist in Chicago, a diverse city with continued neighborhood segregation.

Methods

Using data from the United States Renal Data System (USRDS) and the US Census, we investigated time from dialysis initiation to kidney transplant waitlisting for African American and white patients in Chicago using cause‐specific proportional hazards analyses, adjusting for individual sociodemographic and clinical characteristics, as well as neighborhood poverty and racial composition.

Results

In Chicago, African Americans are significantly less likely than whites to appear on the renal transplant waitlist (HR 0.73, P < .05). Compared to whites in nonpoor neighborhoods, African Americans in poor neighborhoods are significantly less likely to appear on the transplant waitlist (HR 0.61, P < .05). Over 69% of African Americans with ESRD live in these neighborhoods.

Conclusions

Consistent with national data, African Americans in Chicago have a lower likelihood of waitlisting than whites. This disparity is explained in part by neighborhood poverty, which impacts the majority of African American ESRD patients in Chicago.
Cutaneous refractile foreign body microemboli with intravascular injection of oral medication
Authors: Bercovici Nicholas , Russomanno Kristen , Santoro Frank , Scola Christopher , Murphy Michael , Elaba Zendee
Published: February 2018

Injection drug abuse (IDA) is known to cause a spectrum of systemic and cutaneous complications. Despite the increasing incidence of IDA around the world, there is a paucity of literature discussing cutaneous complications from a dermatopathologic perspective. We present a case of a 35‐year‐old male with a complex medical history of Von Willebrand disease, Beçhet disease and diverticular disease. Following a sigmoidectomy/colostomy for diverticular perforation, he presented with fever and an indurated right arm displaying livedoid purpura. The right distal fingertips showed purpura with focal ulceration. A punch biopsy of the right wrist did not show evidence of inflammatory vasculitis or pyogenic infection, but instead showed a focus of polarizing, refractile material occluding a dilated arterial lumen within the mid‐dermis. The patient admitted to injecting a suspension of crushed ondansetron (Zofran) tablets into the antecubital area to control post‐operative nausea. It is known that direct intravascular injection of foreign material can cause distal ischemia and necrosis, either by local vasoconstriction, thrombosis, or formation of microemboli, as in this patient. Our objective is to bring awareness to this rarely reported phenomenon, and to raise clinical suspicion for IDA when confronted with such a unique vasculopathic pattern.
Researching the decline in adolescent drinking: The need for a global and generational approach
Authors: Pennay Amy , Holmes John , Törrönen Jukka , Livingston Michael , Kraus Ludwig , Room Robin
Published: February 2018

Adolescent alcohol consumption has been in decline across many high‐income countries since the early to mid‐2000s. This is a significant public health trend, with few documented examples from history where such a global downward shift in alcohol consumption has occurred primarily among the adolescent segment of the population. In this commentary we describe the nature and breadth of the trend; reflect on the environmental, social and policy factors that have been proffered; and argue that to adequately understand and support the maintenance of these trends, three important methodological considerations are needed for future research. Firstly, longitudinal panel and qualitative studies are needed to complement and inform continuing cross‐sectional research. Secondly, a collaborative cross‐cultural approach is needed to contextualise the international scale of the trend and thirdly, future research must be situated within a historical and generational perspective to understand declines in adolescent drinking in the context of a broader shift in adolescent behaviours.
The effect on emergency department visits of raised alcohol minimum prices in Saskatchewan, Canada
Authors: Sherk Adam , Stockwell Tim , Callaghan Russell C.
Published: February 2018

Introduction and Aims

The province of Saskatchewan, Canada introduced minimum prices graded by alcohol strength in April 2010. As previous research found this intervention significantly decreased alcohol consumption and alcohol‐attributable morbidity, we aim to test the association between the intervention and the rate of emergency department (ED) visits in four alcohol‐related injury categories [motor vehicle collisions (MVC), assaults, falls and total alcohol‐related injuries].

Design and Methods

Data on ED visits in the city of Regina were obtained from the Saskatchewan Ministry of Health. Auto‐regressive integrated moving average time series models were used to test the immediate and lagged effects of the pricing intervention on rates of alcohol‐related nighttime. ED visits and controlled for daytime rates of ED visits, economic variables, linear and seasonal trends, and auto‐regressive and moving average effects.

Results

The implementation of an alcohol minimum pricing strategy in Saskatchewan was associated with decreased MVC‐related ED visits for women aged 26 and over after a 6 month lag period (−39.4%, P < 0.001). There was no significant abrupt effect of this intervention on ED visits of four injury types in any of four gender‐age categories; however, rates of ED visits among young males for MVCs and assaults decreased substantially during this study.

Discussion and Conclusions

The minimum pricing policy change led to a lagged decrease in motor vehicle‐collision‐related ED visits for women older than 25. Of note, there did not appear to be an instantaneous effect on the rate of alcohol‐related injury ED visits immediately after the policy implementation nor lagged effects for other gender‐age groups.
Public Authority and Conservation in Areas of Armed Conflict: Virunga National Park as a ‘State within a State’ in Eastern Congo
Authors: Marijnen Esther
Published: February 2018

Much research on nature conservation in war‐torn regions focuses on the destructive impact of violent conflict on protected areas, and argues that transnational actors should step up their support for those areas to mitigate the risks that conflict poses to conservation efforts there. Overlooked are the effects transnational efforts have on wider conflict dynamics and structures of public authority in these regions. This article describes how transnational actors increasingly gained influence over the management of Virunga National Park in eastern Democratic Republic of Congo (DRC), and how these actors contributed to the militarization of conservation in Virunga. Most scholarly literature suggests that ‘green militarization’ contributes to the extension of state authority over territory and population, yet this is not the case in Virunga. Instead, the militarization of Virunga translates into practices of extra‐state territorialization, with the result that many in the local population perceive the park's management as a project of personalized governance and/or a ‘state within a state’. This article thus argues that it is important to depart from an a priori notion of the ‘state’ when considering the nexus of conservation practices and territorialization, and to analyse this intersection through the lens of public authority instead.
Dulaglutide 1.5 mg as an add‐on option for patients uncontrolled on insulin: Subgroup analysis by age, duration of diabetes and baseline glycated haemoglobin concentration
Authors: Pantalone Kevin M. , Patel Hiren , Yu Maria , Fernández Landó Laura
Published: February 2018

Aims

To assess efficacy and safety of dulaglutide 1.5 mg combined with insulin, categorized by subgroups of baseline glycated haemoglobin (HbA1c; ≤9% and >9% [≤74.9 and >74.9 mmol/mol]), age (<65 and ≥65 years), and duration of diabetes (<10 and ≥10 years) at 6 months in patients with type 2 diabetes (T2D).

Materials and methods

This pooled analysis was conducted in a population of patients with T2D with similar baseline characteristics who were included in the AWARD‐4 and AWARD‐9 clinical trials and randomized to dulaglutide 1.5 mg (pooled mean baseline age 59 years, duration of diabetes 13 years, HbA1c 8.4% [68.3 mmol/mol]). Weight and hypoglycaemia were analysed by individual trial. In AWARD‐4, dulaglutide plus lispro three times daily was assessed against glargine plus lispro three times daily. In AWARD‐9, dulaglutide added to glargine was assessed against placebo added to glargine. Insulins were titrated to target in both trials.

Results

A total of 445 patients were included in this analysis (73% with HbA1c ≤9%, 27% [≤74.9 mmol/mol] with HbA1c >9% [>74.9 mmol/mol]; 70% aged <65 years, 30% aged ≥65 years; 36% with duration of diabetes <10 years, 64% with duration of diabetes ≥10 years). At 6 months, dulaglutide 1.5 mg significantly reduced HbA1c in all subgroups (P < .001), with the highest reduction observed in patients with baseline HbA1c >9% (>74.9 mmol/mol) (range − 1.3% to −2.5% [−14.2 to −27.3 mmol/mol]). The incidence rates of documented symptomatic and severe hypoglycaemia were similar in all subgroups in both trials. The most common adverse events observed in each trial were gastrointestinal in nature.

Conclusion

Dulaglutide 1.5 mg combined with basal or prandial insulin is efficacious for patients with T2D irrespective of age, duration of diabetes or baseline HbA1c.
Direct medical costs of diabetes mellitus in the year of mortality and year preceding the year of mortality
Authors: Wong Carlos K. H. , Jiao Fangfang , Tang Eric H. M. , Tong Thaison , Thokala Praveen , Lam Cindy L. K.
Published: February 2018

Aim

To report the health resource use and estimate the direct medical costs among patients with diabetes mellitus (DM) in the year of mortality and the year preceding the year of mortality.

Materials and methods

We analysed data from a population‐based, retrospective cohort study including all adults with a DM diagnosis in Hong Kong between 2009 and 2013, and who died between January 1, 2010 and December 31, 2013. The annual direct medical costs in the year of mortality and the year preceding the year of mortality were determined by summing the costs of health services utilized within the respective year. The costs were analysed by gender, the presence of comorbidities, diabetic complications and primary cause of death.

Results

A total of 10 649 patients met the eligibility criteria for analysis. On average, the direct medical costs in the year of death were 1.947 times higher than those in the year before death. Men and women with DM incurred similar costs in the year preceding the year of mortality and in the mortality year. Patients with any diabetic complications incurred greater costs in the year of mortality and the year before mortality than those without.

Conclusions

This analysis provides new evidence on incorporating additional direct medical costs in the mortality year, and refining the structure of total cost estimates for use in costing and cost‐effectiveness analyses of interventions for DM.
Macroecological and macroevolutionary patterns emerge in the universe of GNU/Linux operating systems
Authors: Keil Petr , MacDonald A. A. M. , Ramirez Kelly S. , Bennett Joanne M. , García-Peña Gabriel E. , Yguel Benjamin , Bourgeois Bérenger , Meyer Carsten
Published: February 2018

What leads to classically recognized patterns of biodiversity remains an open and contested question. It remains unknown if observed patterns are generated by biological or non‐biological mechanisms, or if we should expect the patterns to emerge in non‐biological systems. Here, we employ analogies between GNU/Linux operating systems (distros), a non‐biological system, and biodiversity, and we look for a number of well‐established ecological and evolutionary patterns in the Linux universe. We demonstrate that patterns of the Linux universe generally match macroecological patterns. Particularly, Linux distro commonness and rarity follow a skewed distribution with a clear excess of rare distros, we observed a power law mean‐variance scaling of temporal fluctuation, but there is only a weak relationship between niche breadth (number of software packages) and commonness. The diversity in the Linux universe also follows general macroevolutionary patterns: the number of phylogenetic lineages increases linearly through time, with clear per‐species diversification and extinction slowdowns, something that has been indirectly estimated, but not directly observed in biology. Moreover, the composition of functional traits (software packages) exhibits significant phylogenetic signal. The emergence of macroecological patterns across Linux suggests that the patterns are produced independently of system identity, which points to the possibility of non‐biological drivers of fundamental biodiversity patterns. At the same time, our study provides a step towards using Linux as a model system for exploring macroecological and macroevolutionary patterns.
Competition between the native and the introduced hornets Vespa crabro and Vespa velutina: a comparison of potentially relevant life‐history traits
Authors: CINI ALESSANDRO , CAPPA FEDERICO , PETROCELLI IACOPO , PEPICIELLO IRENE , BORTOLOTTI LAURA , CERVO RITA
Published: February 2018

1. Invasive alien species are a major threat to biodiversity. In addition to predation and parasitism, native species might suffer from competition when invasive alien species occupy a similar ecological niche.

2. This study focused on the potential interspecific interaction between two hornets: the Asian yellow‐legged hornet, Vespa velutina, a high‐concern invasive alien species recently arrived in Europe; and the native European hornet, Vespa crabro. The two species share a similar ecological niche and V. velutina is rapidly expanding across Europe, which suggests that V. crabro might suffer from competition.

3. Under laboratory‐controlled conditions, two life‐history traits that might cause the two species to compete were investigated: (i) the ability of workers to find food sources and their flexibility in exploiting them (through individual food item choice tests and exploration assays); and (ii) the worker resistance to pathogens (through immune challenge tests).

4. The results show that trophic preference of both species highly overlaps, with a marked dietary preference for honeybees compared with other insect prey and non‐prey protein items. No differences were observed in the exploratory behaviour of both species. Finally, constitutive antibacterial activity was greater in workers of the native species than in workers of the invasive hornet.

5. This laboratory study provides a first assessment under controlled conditions of the factors affecting competition between workers of two hornet species and proposes a framework to assess, in wild contexts, the magnitude of the competition and the impact of the introduced V. velutina on the native V. crabro.
UK shocks and Irish business cycles, 1922–79
Authors: Stuart Rebecca
Published: February 2018

This article examines the transmission of UK and global shocks to the Irish economy over the period 1922–79, using annual data for consumer prices and real GDP in a structural vector autoregression (SVAR) model. UK aggregate demand and supply shocks have large and significant effects on Irish CPI, but smaller effects on Irish real GDP. A historical decomposition indicates that UK aggregate supply and demand shocks played a more important role than domestic shocks in the evolution of Irish CPI. In contrast, the evolution of Irish real GDP is driven more by idiosyncratic domestic shocks than by UK shocks.
Saccade frequency response to visual cues during gait in Parkinson's disease: the selective role of attention
Authors: Stuart Samuel , Lord Sue , Galna Brook , Rochester Lynn
Published: February 2018

Gait impairment is a core feature of Parkinson's disease (PD) with implications for falls risk. Visual cues improve gait in PD, but the underlying mechanisms are unclear. Evidence suggests that attention and vision play an important role; however, the relative contribution from each is unclear. Measurement of visual exploration (specifically saccade frequency) during gait allows for real‐time measurement of attention and vision. Understanding how visual cues influence visual exploration may allow inferences of the underlying mechanisms to response which could help to develop effective therapeutics. This study aimed to examine saccade frequency during gait in response to a visual cue in PD and older adults and investigate the roles of attention and vision in visual cue response in PD. A mobile eye‐tracker measured saccade frequency during gait in 55 people with PD and 32 age‐matched controls. Participants walked in a straight line with and without a visual cue (50 cm transverse lines) presented under single task and dual‐task (concurrent digit span recall). Saccade frequency was reduced when walking in PD compared to controls; however, visual cues ameliorated saccadic deficit. Visual cues significantly increased saccade frequency in both PD and controls under both single task and dual‐task. Attention rather than visual function was central to saccade frequency and gait response to visual cues in PD. In conclusion, this study highlights the impact of visual cues on visual exploration when walking and the important role of attention in PD. Understanding these complex features will help inform intervention development.
Impact of anemia on in‐hospital complications after ischemic stroke
Authors: Wei C.‐C. , Zhang S.‐T. , Tan G. , Zhang S.‐H. , Liu M.
Published: February 2018

Background and purpose

In‐hospital complications after stroke represent barriers to optimal recovery and are even potentially life‐threatening. Anemia is common in stroke patients and is related to poor outcome after stroke. Less is known, however, of the association of anemia with complications. We aimed to investigate the impact of anemia on a series of in‐hospital complications after ischemic stroke.

Methods

Consecutive patients with ischemic stroke within 7 days were included. Anemia on admission and its severity were defined according to World Health Organization criteria. Eight pre‐specified complications, such as pneumonia, gastrointestinal bleeding (GIB) and hemorrhagic transformation, were recorded during hospitalization.

Results

A total of 2647 patients were included. Anemia was present in 648 patients (24.5%), and 883 patients (33.4%) experienced at least one complication. Patients with anemia were more likely to experience one or more complications, pneumonia, GIB and thromboembolism (all P < 0.001) than patients without anemia. After adjustment for the confounders, patients with anemia had an adjusted odds ratio for at least one complication of 1.539 [95% confidence interval (CI), 1.232–1.923], for pneumonia of 1.707 (95% CI, 1.345–2.167), for GIB of 2.245 (95% CI, 1.215–4.148) and for thromboembolism of 3.443 (95% CI, 1.668–7.108). The risk of at least one complication, pneumonia, GIB and thromboembolism increased with anemia severity (all P < 0.05). There was no significant association between anemia and urinary tract infection, hemorrhagic transformation, seizures and brain herniation.

Conclusion

Anemia is an independent predictor of in‐hospital complications following stroke, especially for pneumonia, GIB and thromboembolism. It remains to be studied whether prophylaxis and treatment of anemia would prevent in‐hospital complications.
Influence of intergenotypic competition on multigenerational persistence of abiotic stress resistance transgenes in populations of Arabidopsis thaliana
Authors: Bigelow Patrick J. , Loescher Wayne , Hancock James F. , Grumet Rebecca
Published: February 2018

Reducing crop losses due to abiotic stresses is a major target of agricultural biotechnology that will increase with climate change and global population growth. Concerns, however, have been raised about potential ecological impacts if transgenes become established in wild populations and cause increased competitiveness of weedy or invasive species. Potential risks will be a function of transgene movement, population sizes, and fitness effects on the recipient population. While key components influencing gene flow have been extensively investigated, there have been few studies on factors subsequent to transgene movement that can influence persistence and competitiveness. Here, we performed multiyear, multigenerational, assessment to examine fitness effects and persistence of three mechanistically different abiotic stress tolerance genes: C‐repeat binding factor 3/drought responsive element binding factor 1a (CBF3/DREB1a); Salt overly sensitive 1 (SOS1); and Mannose‐6‐phosphate reductase (M6PR). Transgenic Arabidopsis thaliana overexpressing these genes were grown in pure populations and in competition with wild‐type (WT) parents for six generations spanning a range of field environment conditions. Growth, development, biomass, seed production, and transgene frequency were measured at each generation. Seed planted for each generation was obtained from the previous generation as would occur during establishment of a new genotype in the environment. The three transgenes exhibited different fitness effects and followed different establishment trajectories. In comparison with pure populations, CBF3 lines exhibited reduced dry weight, seed yield, and viable seed yield, relative to WT background. In contrast, overexpression of SOS1 and M6PR did not significantly impact productivity measures in pure populations. In competition with WT, negative fitness effects were magnified. Transgene frequencies were significantly reduced for CBF3 and SOS1 while frequencies of M6PR appeared to be subject to genetic drift. These studies demonstrate the importance of fitness effects and intergenotype competition in influencing persistence of transgenes conferring complex traits.
Colonizing Islands of water on dry land—on the passive dispersal of fish eggs by birds
Authors: Hirsch Philipp Emanuel , N'Guyen Anouk , Muller Roxane , Adrian‐Kalchhauser Irene , Burkhardt‐Holm Patricia
Published: February 2018

The vast majority of global freshwater ecosystems are small lakes with less than 100 m2 surface area. These lakes are often unconnected to other water bodies but frequently host fish populations. Existing explanations for how fish colonize such remote habitats often involve birds as vectors transporting fish eggs as propagules. In this study, we aim to quantify the prevalence of these explanations among relevant societal groups as well as their scientific knowledge basis. We analyzed entries in online blogs and forums and surveyed the opinions of local stakeholders and decision makers using a questionnaire. To collect published scientific knowledge, we conducted a structured literature review. Our results reveal a discrepancy between commonly found beliefs and the empirical knowledge supporting those beliefs: Dispersal of fish eggs by water birds was overall the most frequent explanation online and in the questionnaire. In the scientific literature, however, we found hardly any empirical research on passive fish egg dispersal. We propose research directions for how to close this gap of knowledge and suggest that future empirical studies on passive fish egg dispersal may be inspired by existing work on passive dispersal in aquatic invertebrates. Mitigating the belief‐evidence discrepancy on fish dispersal will be essential to better understand the patterns of fish biodiversity across landscapes, to counteract its losses, and inform management strategies for invasive fish species.
Economic, ecological and genetic impacts of marine stock enhancement and sea ranching: A systematic review
Authors: Kitada Shuichi
Published: February 2018

Hatchery release is one of the most popular management tools in fisheries, forestry and wild life management, while its negative impacts on wild populations are a global concern. Research and monitoring of its impacts are generally lacking, and the usefulness of hatchery release for fisheries and conservation objectives is unclear. Here, I evaluated positive and negative impacts of worldwide marine stock enhancement and sea ranching programmes in a systematic review associated with meta‐analyses with the goal of reducing bias of the review. Vast numbers of individuals of more than 180 species are released into the wild each year, but most studies are at experimental stages to assess its potential, and empirical studies are sparse for evaluating the impact on fishery production. Most cases are economically unprofitable except for a few successful cases or unevaluated. The effects of releasing juveniles can be dwarfed by the magnitude of natural recruitment when the spawning stock produces much larger recruitment than released juveniles. Density‐dependent growth caused by competition of food can be substantial, and growth rates of hatchery and wild fish and other competitive species can simultaneously be reduced when stocking exceeded the carrying capacity. Relative reproductive success can vary depending on the species, seed quality and environmental factors. Empirical studies show evidence of substantial gene flow from hatcheries, but fitness reduction in stocked populations has not been reported. The results represent the current state of worldwide marine stock enhancement and sea ranching activity and provide key information for growing fields of artificial propagation and conservation.
Individual movements, home ranges and habitat use by native rheophilic cyprinids and non‐native catfish in a large regulated river
Authors: Capra H. , Pella H. , Ovidio M.
Published: February 2018

The mobility patterns of two native species, barbel, Barbus barbus (L.) and chub, Squalius cephalus (L.), and of one non‐native fish species, the catfish Silurus glanis (L.), were assessed on a 35.5‐km reach of the Upper Rhône River, a strong flowing river with notable thermal regime alterations. An active acoustic tracking technique adapted to large rivers allowed (1) the identification of longitudinal home ranges, movements and preferred habitat at large scale, and (2) the analysis of the influence of discharge and water temperature on the movement patterns of the fish. The active fish‐tracking system recorded 1,572 fish localisations over 7 months on a weekly basis for 80% of the tagged fish (37 barbel, 23 chub and 13 catfish). Compared with the catfish, barbel and chub showed wider longitudinal home ranges, more movements >1 km and higher interindividual variability. The catfish preferred artificially heated habitats with less morphological diversity. The three species were more often localised in river sections with high density of woody debris. The results suggest that habitat degradation is more damaging for cyprinids in large modified rivers, while the catfish seemed less, impacted.
Quantifying and predicting the benefits of environmental flows: Combining large‐scale monitoring data and expert knowledge within hierarchical Bayesian models
Authors: Webb J. Angus , de Little Siobhan C. , Miller Kimberly A. , Stewardson Michael J.
Published: February 2018

Despite large investments of public funds into environmental flows programs, we have little ability to make quantitative predictions of the ecological benefits of restored flow regimes. Rather, ecological predictions in environmental flow assessments typically have been qualitative and based largely upon expert opinion. Widely applicable, quantitative models would help to justify existing flow programs and to inform future planning.

Here, we used a hierarchical Bayesian analysis of monitoring data coupled with expert‐derived prior distributions, to develop such a model. We quantified the relationship between the duration and frequency of inundation, and encroachment of terrestrial vegetation into regulated river channels. The analysis was informed by data from 27 sites on seven rivers.

We found that longer inundation durations reduce terrestrial vegetation encroachment. For example, a 50‐day continuous inundation during winter reduced predicted vegetation cover to a median of 11% (95% CI: 7%–35%) of cover predicted under non‐inundated conditions. This effect varied among sites and rivers, and was moderated by the frequency of inundation events.

The hierarchical structure improved precision of model predictions relative to simpler analysis structures. Informative prior distributions also improved precision relative to minimally informative priors.

The hierarchical Bayesian analysis allows us to make quantitative predictions of ecological response under the full range of flow conditions, allowing us to assess the benefits of planned or delivered environmental flows. It can be used to make estimates of ecological effects at sites that have not been sampled, and also to scale up site‐level results to catchment and regional scales. Quantitative predictions of ecological effects provide a more objective risk‐based approach, allowing improved planning of environmental flows and building public confidence in these major investments of public funds.
Crayfish invasion facilitates dispersal of plants and invertebrates by gulls
Authors: Lovas‐Kiss Ádám , Sánchez Marta I. , Molnár V. Attila , Valls Luis , Armengol Xavier , Mesquita‐Joanes Francesc , Green Andy J.
Published: February 2018

The red swamp crayfish (Procambarus clarkii), originally from North America, is one of the world's worst aquatic invaders. It is a favoured prey item for waterbirds, but the influence of this novel predator–prey relationship on dispersal of other organisms has not previously been considered. We investigated the potential for dispersal of plants and invertebrates by migratory waterbirds feeding on alien P. clarkii in European ricefields at harvest time.

In November–December of 2014–2015, we collected propagules from the outside of 13 crayfish captured as they moved out of ricefields during harvest in Doñana, south‐west Spain. We also collected excreta (N = 76 faeces, 14 pellets) of lesser‐black backed gull (Larus fuscus).

We recorded diaspores from at least 11 plant species (161 seeds from 10 angiosperm taxa, and 14 charophyte oogonia) on the outside of crayfish, together with 54 eggs from eight aquatic invertebrate taxa. Adults and juveniles of at least nine microcrustaceans, including the alien ostracods Hemicypris reticulata and Ankylocythere sinuosa, were also recovered from crayfish. No intact propagules were present in the digestive system of the crayfish.

Contents of regurgitated pellets confirmed P. clarkii as the main food item for gulls. Diaspores from at least 12 plant species (154 seeds from 11 angiosperm taxa, and 17 charophyte oogonia) were recovered from gull excreta, together with 129 eggs of 12 aquatic invertebrate taxa. A statoblast of the alien bryozoan Plumatella vaihiriae was found in gull faeces. Seven of the plant species are important agricultural weeds, and two are alien to Spain. Diaspores from six plant taxa were germinated, confirming viability. These propagules were from a similar set of plants and invertebrates to those found on the outside of crayfish, suggesting that propagules in gull excreta were ingested inadvertently with their crayfish prey.

Ricefields constitute a major artificial aquatic habitat covering an increasing proportion of the world's land surface and typically support native or alien crayfish. Crayfish invasion can lead to novel secondary dispersal pathways for plants and invertebrates through interactions with their predators, promoting the expansion of alien and native species (including weeds) through long‐distance dispersal via migratory waterbirds and increasing connectivity of organisms between artificial and natural ecosystems. This represents a previously overlooked impact of crayfish invasion on ecosystem services.
Long‐term organic carbon sequestration in tidal marsh sediments is dominated by old‐aged allochthonous inputs in a macrotidal estuary
Authors: Van de Broek Marijn , Vandendriessche Caroline , Poppelmonde Dries , Merckx Roel , Temmerman Stijn , Govers Gerard
Published: February 2018

Tidal marshes are vegetated coastal ecosystems that are often considered as hotspots of atmospheric CO2 sequestration. Although large amounts of organic carbon (OC) are indeed being deposited on tidal marshes, there is no direct link between high OC deposition rates and high OC sequestration rates due to two main reasons. First, the deposited OC may become rapidly decomposed once it is buried and, second, a significant part of preserved OC may be allochthonous OC that has been sequestered elsewhere. In this study we aimed to identify the mechanisms controlling long‐term OC sequestration in tidal marsh sediments along an estuarine salinity gradient (Scheldt estuary, Belgium and the Netherlands). Analyses of deposited sediments have shown that OC deposited during tidal inundations is up to millennia old. This allochthonous OC is the main component of OC that is effectively preserved in these sediments, as indicated by the low radiocarbon content of buried OC. Furthermore, OC fractionation showed that autochthonous OC is decomposed on a decadal timescale in saltmarsh sediments, while in freshwater marsh sediments locally produced biomass is more efficiently preserved after burial. Our results show that long‐term OC sequestration is decoupled from local biomass production in the studied tidal marsh sediments. This implies that OC sequestration rates are greatly overestimated when they are calculated based on short‐term OC deposition rates, which are controlled by labile autochthonous OC inputs. Moreover, as allochthonous OC is not sequestered in‐situ, it does not contribute to active atmospheric CO2 sequestration in these ecosystems. A correct assessment of the contribution of allochthonous OC to the total sedimentary OC stock in tidal marsh sediments as well as a correct understanding of the long‐term fate of locally produced OC are both necessary to avoid overestimations of the rate of in‐situ atmospheric CO2 sequestration in tidal marsh sediments.
Wingless signaling regulates winner/loser status in Minute cell competition
Authors: Akai Nanami , Igaki Tatsushi , Ohsawa Shizue
Published: February 2018

Cells heterozygously mutant for a ribosomal protein gene, called Minute/+ mutants, are eliminated from epithelium by cell competition when surrounded by wild‐type cells. Whereas several factors that regulate Minute cell competition have been identified, the mechanisms how winner/loser status is determined and thereby triggers cell competition are still elusive. To address this, we established two assay systems for Minute cell competition, namely (i) the CORE (competitive elimination of RpS3‐RNAi‐expressing cells) system in which RpS3‐RNAi‐expressing wing pouch cells are eliminated from wild‐type wing disc and (ii) the SURE (supercompetition of RpS3‐expressing clones in RpS3/+ tissue) system in which RpS3‐over‐expressing clones generated in RpS3/+ wing disc outcompete surrounding RpS3/+ cells. An ectopic over‐expression screen using the CORE system identified Wg signaling as a critical regulator of Minute cell competition. Activation of Wg signaling in loser cells suppressed their elimination, whereas down‐regulation of Wg signaling in loser cells enhanced their elimination. Furthermore, using the SURE system, we found that down‐regulation of Wg signaling in winner cells suppressed elimination of neighboring losers. Our observations suggest that cellular Wg signaling activity is crucial for determining winner/loser status and thereby triggering Minute cell competition.