178 research outputs found
A paleoecological context for forest distribution and restoration in Grootbos Nature Reserve, Agulhas Plain, South Africa
Grootbos Nature Reserve falls within the Cape Floristic Region of South Africa and comprises fynbos and forest vegetation elements, which exist as alternate stable states and are naturally maintained by feedbacks between vegetation, fire, topography and climate. The objective of this study was to investigate changes in forest extent in the Baviaansfontein valley in Grootbos Nature Reserve in order to understand whether current forest coverage was greater or lesser prior to colonial settlement. Incorporating paleoecology has the potential to define historical ranges of landscape variability that can guide forest restoration programs that are aligned to historical forest occurrence. Not all landscapes are suited for tree planting initiatives as they harbor indigenous open vegetation, which is of conservation value. Historical and palaeoecological information is especially valuable as tree planting initiatives and reforestation programs are becoming more popular. Here we present a combined palynological (pollen, spores, charcoal) and geochemical approach (X-ray fluorescence elemental ratios, Loss-on-ignition), to evaluate the historic extent and distribution of forest and fynbos vegetation for the past ~250 years at Baviaansfontein in the Grootbos Nature Reserve. The start of the record was dominated by pollen typical of asteraceous fynbos, with evidence of forest elements also present, though in low abundance. After 200 years (c.1750 CE–1950 CE) of increased input of micro- and macrocharcoal, the subsequent decline in charcoal indicates a decrease in fire occurrence. This decline coincides with increased input of forest pollen taxa, suggesting that fire suppression most likely triggered forest expansion and perhaps initiated the beginning of a biome boundary shift. The continued decline in fire promoted the development of the present-day proteoid fynbos type around ~1980 CE and was responsible for the replacement of the previously more asteraceous-dominated fynbos type. The results show that changes in fire occurrence have driven compositional changes over time within fynbos but also contributed to the expansion of forest at the expense of fynbos. Considering the palaeoecological record and the expected warmer climate with more fires, forest expansion at Baviaansfontein is not recommended. The proteoid-dominated fynbos biome might be similarly negatively affected by warmer climate and a shift to an asteraceous fynbos community could occur in the future
PatologĂa dual y trastornos mentales en reclusos consumidores de sustancias
The aims of this study were to determine the frequency of dual pathology and suicide risks in substance-using prisoners and to analyze the factors associated with their development. The sample consisted of 143 prisoners (95.8% male) confined in the prison of Villabona (Asturias, Spain). Descriptive and logistic regression analyses were used. Thirty-five percent of inmates were found to have a dual diagnosis and 60.6% of this subsample presented risk of suicide. We found that to have been a childhood victim of physical abuse increases the likelihood of developing substance use disorder, anxiety disorder and/or dual pathology. However, having been a victim of psychological abuse raises the risk of developing mood and psychotic disorders.Los objetivos de este estudio fueron evaluar la frecuencia de patologĂa dual y de riesgo de suicidio en personas consumidoras de sustancias internadas en prisiĂłn e investigar los factores asociados con su desarrollo. La muestra estuvo compuesta por 143 reclusos (95,8% varones) ingresados en el centro penitenciario de Villabona (Asturias). Se realizaron análisis descriptivos y de regresiĂłn logĂstica. Un 35% de los internos presentaron patologĂa dual, de los cuales el 60,6% presentĂł tambiĂ©n riesgo de suicidio. Se observĂł asimismo que la presencia de malos tratos fĂsicos en la infancia incrementa la probabilidad de desarrollar un trastorno por consumo de sustancias, de ansiedad y/o patologĂa dual. Por el contrario, la exposiciĂłn al maltrato psicolĂłgico eleva el riesgo de desarrollo de trastornos afectivos y psicĂłticos.
Linguistics
Contains table of contents for Section 4, an introduction and abstracts for eleven doctoral dissertations
Understanding, comprehensibility and acceptance of an evidence-based consumer information brochure on fall prevention in old age: a focus group study
<p>Abstract</p> <p>Background</p> <p>Evidence-based patient and consumer information (EBPI) is an indispensable component of the patients' decision making process in health care. Prevention of accidental falls in the elderly has gained a lot of public interest during preceding years. Several consumer information brochures on fall prevention have been published; however, none fulfilled the criteria of an EBPI. Little is known about the reception of EBPI by seniors. Therefore we aimed to evaluate a recently developed EBPI brochure on fall prevention with regard to seniors' acceptance and comprehensibility in focus groups and to explore whether the participants' judgements differed depending on the educational background of the study participants.</p> <p>Methods</p> <p>Seven focus groups were conducted with 40 seniors, aged 60 years or older living independently in a community. Participants were recruited by two gatekeepers. A discussion guide was used and seniors were asked to judge the EBPI brochure on fall prevention using a Likert scale 1-6. The focus group discussions were tape recorded, transcribed verbatim, and analysed using content analysis.</p> <p>Results</p> <p>The participants generally accepted the EBPI brochure on fall prevention. Several participants expressed a need for more practical advice. The comprehensibility of the brochure was influenced positively by brief chapter summaries. Participants dismissed the statistical illustrations such as confidence intervals or a Fagan nomogram and only half of them agreed with the meta-information presented in the first chapter. The detailed information about fall prevalence was criticised by some seniors. The use of a case story was well tolerated by the majority of participants.</p> <p>Conclusion</p> <p>Our findings indicate that the recently developed EBPI brochure on fall prevention in old age was generally well accepted by seniors, but some statistical descriptions were difficult for them to understand. The brochure has to be updated. However, not all issues raised by the participants will be taken into account since some of them are contrary to the principles of EBPI.</p
Tolerance of allogromiid Foraminifera to severely elevated carbon dioxide concentrations : implications to future ecosystem functioning and paleoceanographic interpretations
Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Global and Planetary Change 65 (2009): 107-114, doi:10.1016/j.gloplacha.2008.10.013.Increases in the partial pressure of carbon dioxide (pCO2) in the atmosphere will
significantly affect a wide variety of terrestrial fauna and flora. Because of tight atmospheric-oceanic
coupling, shallow-water marine species are also expected to be affected by increases in
atmospheric carbon dioxide concentrations. One proposed way to slow increases in atmospheric
pCO2 is to sequester CO2 in the deep sea. Thus, over the next few centuries marine species will
be exposed to changing seawater chemistry caused by ocean-atmospheric exchange and/or deep-ocean
sequestration. This initial case study on one allogromiid foraminiferal species
(Allogromia laticollaris) was conducted to begin to ascertain the effect of elevated pCO2 on
benthic Foraminifera, which are a major meiofaunal constituent of shallow- and deep-water
marine communities. Cultures of this thecate foraminiferan protist were used for 10-14-day
experiments. Experimental treatments were executed in an incubator that controlled CO2 (15
000; 30 000; 60 000; 90 000; 200 000 ppm), temperature and humidity; atmospheric controls
(i.e., ~375 ppm CO2) were executed simultaneously. Although the experimental elevated pCO2
values are far above foreseeable surface water pCO2, they were selected to represent the
spectrum of conditions expected for the benthos if deep-sea CO2 sequestration becomes a reality.
Survival was assessed in two independent ways: pseudopodial presence/absence and
measurement of adenosine triphosphate (ATP), which is an indicator of cellular energy.
Substantial proportions of A. laticollaris populations survived 200 000 ppm CO2 although the
mean of the median [ATP] of survivors was statistically lower for this treatment than for that of
atmospheric control specimens. After individuals that had been incubated in 200 000 ppm CO2
for 12 days were transferred to atmospheric conditions for ~24 hours, the [ATP] of live
specimens (survivors) approximated those of the comparable atmospheric control treatment.
Incubation in 200 000 ppm CO2 also resulted in reproduction by some individuals. Results
suggest that certain Foraminifera are able to tolerate deep-sea CO2 sequestration and perhaps
thrive as a result of elevated pCO2 that is predicted for the next few centuries, in a high-pCO2
world. Thus, allogromiid foraminiferal “blooms” may result from climate change. Furthermore,
because allogromiids consume a variety of prey, it is likely that they will be major players in
ecosystem dynamics of future coastal sedimentary environments.This work was funded by US Department of Energy grant # DE-FG02-03ER63696 (to
J. Kennett and J. Bernhard), NSF OCE-0725966, and the WHOI Summer Student Fellow
Program, which is funded by NSF Research Experience for Undergraduates Program grant
#OCE-0139423
NANOG alone induces germ cells in primed epiblast in vitro by activation of enhancers.
Nanog, a core pluripotency factor in the inner cell mass of blastocysts, is also expressed in unipotent primordial germ cells (PGCs) in mice, where its precise role is yet unclear. We investigated this in an in vitro model, in which naive pluripotent embryonic stem (ES) cells cultured in basic fibroblast growth factor (bFGF) and activin A develop as epiblast-like cells (EpiLCs) and gain competence for a PGC-like fate. Consequently, bone morphogenetic protein 4 (BMP4), or ectopic expression of key germline transcription factors Prdm1, Prdm14 and Tfap2c, directly induce PGC-like cells (PGCLCs) in EpiLCs, but not in ES cells. Here we report an unexpected discovery that Nanog alone can induce PGCLCs in EpiLCs, independently of BMP4. We propose that after the dissolution of the naive ES-cell pluripotency network during establishment of EpiLCs, the epigenome is reset for cell fate determination. Indeed, we found genome-wide changes in NANOG-binding patterns between ES cells and EpiLCs, indicating epigenetic resetting of regulatory elements. Accordingly, we show that NANOG can bind and activate enhancers of Prdm1 and Prdm14 in EpiLCs in vitro; BLIMP1 (encoded by Prdm1) then directly induces Tfap2c. Furthermore, while SOX2 and NANOG promote the pluripotent state in ES cells, they show contrasting roles in EpiLCs, as Sox2 specifically represses PGCLC induction by Nanog. This study demonstrates a broadly applicable mechanistic principle for how cells acquire competence for cell fate determination, resulting in the context-dependent roles of key transcription factors during development.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nature1648
Functional and Molecular Effects of Arginine Butyrate and Prednisone on Muscle and Heart in the mdx Mouse Model of Duchenne Muscular Dystrophy
The number of promising therapeutic interventions for Duchenne Muscular Dystrophy (DMD) is increasing rapidly. One of the proposed strategies is to use drugs that are known to act by multiple different mechanisms including inducing of homologous fetal form of adult genes, for example utrophin in place of dystrophin.In this study, we have treated mdx mice with arginine butyrate, prednisone, or a combination of arginine butyrate and prednisone for 6 months, beginning at 3 months of age, and have comprehensively evaluated the functional, biochemical, histological, and molecular effects of the treatments in this DMD model. Arginine butyrate treatment improved grip strength and decreased fibrosis in the gastrocnemius muscle, but did not produce significant improvement in muscle and cardiac histology, heart function, behavioral measurements, or serum creatine kinase levels. In contrast, 6 months of chronic continuous prednisone treatment resulted in deterioration in functional, histological, and biochemical measures. Arginine butyrate-treated mice gene expression profiling experiments revealed that several genes that control cell proliferation, growth and differentiation are differentially expressed consistent with its histone deacetylase inhibitory activity when compared to control (saline-treated) mdx mice. Prednisone and combination treated groups showed alterations in the expression of genes that control fibrosis, inflammation, myogenesis and atrophy.These data indicate that 6 months treatment with arginine butyrate can produce modest beneficial effects on dystrophic pathology in mdx mice by reducing fibrosis and promoting muscle function while chronic continuous treatment with prednisone showed deleterious effects to skeletal and cardiac muscle. Our results clearly indicate the usefulness of multiple assays systems to monitor both beneficial and toxic effects of drugs with broad range of in vivo activity
Stripping the Boss : The Powerful Role of Humor in the Egyptian Revolution 2011
The Egyptian Revolution 2011 has shaken the Arab world and stirred up Middle-East politics. Moreover, it caused a rush in political science and the neighboring disciplines, which had not predicted an event like this and now have troubles explaining it. While many things can be learned from the popular uprising, and from the limitations of previous scholarship, our focus will be on a moral resource, which has occasionally been noticed, but not sufficiently explored: the role of humor in keeping up the spirit of the Revolution. For eighteen days, protestors persevered at Liberation Square in Central Cairo, the epicenter of resistance; at times a few dozens, at times hundreds of thousands. What they did was to fight the terror of the regime, which reached absurd peaks during those days, with humor – successfully. We offer a social-functionalist account of the uprising, which includes behavioral as well as cultural levels of analysis, and illuminates how humorous means helped to achieve deadly serious goals. By reconstructing how Egyptians laughed themselves into democracy, we outline a social psychology of resistance, which uses humor both as a sword and a shield.Peer reviewe
Use and attitudes of obstetricians toward 3 high-risk interventions in MFMU Network hospitals
We sought to evaluate the frequency of, and factors associated with, the use of 3 evidence-based interventions: antenatal corticosteroids for fetal lung maturity, progesterone for prevention of recurrent preterm birth, and magnesium sulfate for fetal neuroprotection
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