168 research outputs found
How future climatic uncertainty and biotic stressors might influence the sustainability of African vegetable production
The study was conducted to determine whether likely global climatic
uncertainty in the future will pose substantive risk to small-scale vegetable producers
in Africa, and to consider whether climate change threatens the development and
sustainability of improved vegetable horticultural systems in Africa. Annual average
air temperature and rainfall totals were assessed over the period 1975-2014 or,
where possible, for rainfall for longer periods approaching 100 years; the trends in
these data sets were determined through linear regression techniques. Predictions of
the likely values of annual average air temperatures in the next 25, 50, 75 and 100
years were made. Considerable variability in trends is reported ranging from
extremely fast warming in Tunis, Tunisia contrasting with slight cooling in Bamako,
Mali. Annual variability in rainfall was substantive but there were no long-term trends
of consequence, even when considered over the last 100 years. Consequently, the
sustainability of vegetable production will be threatened mostly by changes in pest
(e.g., weeds, insects, fungi, bacteria and viruses) damage to crops in small-scale
production systems. A call is made for national governments to give these issues
enhanced priority in the distribution of future research and capacity-building
resources, as most of these production stressors are under-researched and evident
solutions to such problems are not currently available
Exploiting the functionality of root systems for dry, saline, and nutrient deficient environments in a changing climate
Increasing episodes of drought, lack of sufficient nutrients, exposure to toxic minerals, and soil compaction
are just a few examples of the environmental constraints that the roots are exposed to during plant growth.
Understanding how roots respond to these stresses is crucial for improving crop production under such
conditions. Yet, investigating roots is a very difficult task and, therefore, very little is known about the
precise role that the roots play in contributing to plant adaptation to hostile environments. It is assumed that
while the root depth and abundance would contribute to drought tolerance, profuse rooting would enhance
nutrient capture, and where the membrane transporters would exclude salts from the root cells. However, a
great deal is still unknown about how these mechanisms actually operate; for example which particular
characteristics of roots and root hydraulics actually contributes to water uptake in a way that confers
increased tolerance, how the stress signaling from the roots affects the physiological relations in the shoot
and those between the shoot and the root, how water and nutrient absorption relate to one another when
both are limiting, or how roots avoid the loading of salt in xylem vessels.
In this paper, our intention is not an exhaustive review of roots, but to highlight a few research topics
related to abiotic stresses - mostly drought stress, but also nutrient limitation (especially phosphorus) and
salt stress - where roots and their hydraulics are at the center stage. First, we provide an update on root
structure, root hydraulics, and modes of water and nutrient absorption, mainly focusing on how inter- and
intra-specific variations in these aspects can modify the way roots respond to a range of abiotic stresses.
We then review scattered reports across a range of crops showing the contribution of roots to stress
tolerance, and then report our own assessment of the role of roots using near isogenic lines (NILs
Relearning old lessons for the future of foodâby bread alone no longer: diversifying diets with fruit and vegetables
Diversifying diets and agricultural enterprises
with fruit and vegetables is a potent weapon
in the current global battle against malnutrition
and poverty. Agricultural science can contribute
substantially to enhance the development prospects
and health of not only disadvantaged and
vulnerable individuals at one end of the spectrum
but also the growth and equity of national
economies at the other. Moreover, with relatively
simple applied research, new crop species and
technologies can rapidly enter the development
pathway to benefi t even the poorest people or
nations. More upstream research can help to
guard fruit and vegetable production against the
vagaries of potential climatic uncertainty, which
is projected to become more prominent over
future decades. However, historical and continuing
widespread underinvestment in fruit and
vegetable research and development from the
national to the global level may severely compromise
the worldâs ability to use such highvalue
species for crop diversifi cation and as a
major engine of development growth to ensure
global food and nutritional security
Psychiatric disorders and urbanization in Germany
<p>Abstract</p> <p>Background</p> <p>Epidemiological studies over the last decade have supplied growing evidence of an association between urbanization and the prevalence of psychiatric disorders. Our aim was to examine the link between levels of urbanization and 12-month prevalence rates of psychiatric disorders in a nationwide German population study, controlling for other known risk factors such as gender, social class, marital status and the interaction variables of these factors with urbanization.</p> <p>Methods</p> <p>The Munich Composite International Diagnostic Interview (M-CIDI) was used to assess the prevalence of mental disorders (DSM-IV) in a representative sample of the German population (N = 4181, age: 18â65). The sample contains five levels of urbanization based on residence location.</p> <p>The epidemiological study was commissioned by the German Ministry of Research, Education and Science (BMBF) and approved by the relevant Institutional Review Board and ethics committee. Written informed consent was obtained for both surveys (core survey and Mental Health Supplement). Subjects did not get any financial compensation for their study participation.</p> <p>Results</p> <p>Higher levels of urbanization were linked to higher 12-month prevalence rates for almost all major psychiatric disorders (with the exception of substance abuse and psychotic disorders). The weighted prevalence percentages were highest in the most urbanized category. Alongside urbanization, female gender, lower social class and being unmarried were generally found to be associated with higher levels of psychopathology. The impact of urbanization on mental health was about equal (for almost all major psychiatric disorders) in young people and elderly people, men and women, and in married and single people. Only people from a low social class in the most urbanized settings had more somatoform disorders, and unmarried people in the most urbanized settings had more anxiety disorders.</p> <p>Conclusion</p> <p>Psychiatric disorders are more prevalent among the inhabitants of more urbanized areas. probably because of environmental stressors.</p
Apparent Temperature and Cause-Specific Emergency Hospital Admissions in Greater Copenhagen, Denmark
One of the key climate change factors, temperature, has potentially grave implications for human health. We report the first attempt to investigate the association between the daily 3-hour maximum apparent temperature (Tappmax) and respiratory (RD), cardiovascular (CVD), and cerebrovascular (CBD) emergency hospital admissions in Copenhagen, controlling for air pollution. The study period covered 1 January 2002â31 December 2006, stratified in warm and cold periods. A case-crossover design was applied. Susceptibility (effect modification) by age, sex, and socio-economic status was investigated. For an IQR (8°C) increase in the 5-day cumulative average of Tappmax, a 7% (95% CI: 1%, 13%) increase in the RD admission rate was observed in the warm period whereas an inverse association was found with CVD (â8%, 95% CI: â13%, â4%), and none with CBD. There was no association between the 5-day cumulative average of Tappmax during the cold period and any of the cause-specific admissions, except in some susceptible groups: a negative association for RD in the oldest age group and a positive association for CVD in men and the second highest SES group. In conclusion, an increase in Tappmax is associated with a slight increase in RD and decrease in CVD admissions during the warmer months
Volcanic Gases:Silent Killers
This is the accepted manuscript. The final version is available at http://link.springer.com/chapter/10.1007%2F11157_2015_14.Volcanic gases are insidious and often overlooked hazards. The effects of volcanic gases on life may be direct, such as asphyxiation, respiratory diseases and skin burns; or indirect, e.g. regional famine caused by the cooling that results from the presence of sulfate aerosols injected into the stratosphere during explosive eruptions. Although accounting for fewer fatalities overall than some other forms of volcanic hazards, history has shown that volcanic gases are implicated frequently in small-scale fatal events in diverse volcanic and geothermal regions. In order to mitigate risks due to volcanic gases, we must identify the challenges. The first relates to the difficulty of monitoring and hazard communication: gas concentrations may be elevated over large areas and may change rapidly with time. Developing alert and early warning systems that will be communicated in a timely fashion to the population is logistically difficult. The second challenge focuses on education and understanding risk. An effective response to warnings requires an educated population and a balanced weighing of conflicting cultural beliefs or economic interests with risk. In the case of gas hazards, this may also mean having the correct personal protection equipment, knowing where to go in case of evacuation and being aware of increased risk under certain sets of meteorological conditions. In this chapter we review several classes of gas hazard, the risks associated with them, potential risk mitigation strategies and ways of communicating risk. We discuss carbon dioxide flows and accumulations, including lake overturn events which have accounted for the greatest number of direct fatalities, the hazards arising from the injection of sulfate aerosol into the troposphere and into the stratosphere. A significant hazard facing the UK and northern Europe is a âLakiâ-style eruption in Iceland, which will be associated with increased risk of respiratory illness and mortality due to poor air quality when gases and aerosols are dispersed over Europe. We discuss strategies for preparing for a future Laki style event and implications for society
TRPA1 is essential for the vascular response to environmental cold exposure
This work was supported by the British Heart Foundation and a Capacity Building Award in Integrative Mammalian Biology. It was also supported by Arthritis Research UK and XK is supported by a British Pharmacological Society AJ Clark studentship
Arranjo espacial, densidade e ĂŠpoca de semeadura no acĂşmulo de matĂŠria seca e nutrientes de trĂŞs adubos verdes
Associations between air temperature and cardio-respiratory mortality in the urban area of Beijing, China: a time-series analysis
<p>Abstract</p> <p>Background</p> <p>Associations between air temperature and mortality have been consistently observed in Europe and the United States; however, there is a lack of studies for Asian countries. Our study investigated the association between air temperature and cardio-respiratory mortality in the urban area of Beijing, China.</p> <p>Methods</p> <p>Death counts for cardiovascular and respiratory diseases for adult residents (âĽ15 years), meteorological parameters and concentrations of particulate air pollution were obtained from January 2003 to August 2005. The effects of two-day and 15-day average temperatures were estimated by Poisson regression models, controlling for time trend, relative humidity and other confounders if necessary. Effects were explored for warm (April to September) and cold periods (October to March) separately. The lagged effects of daily temperature were investigated by polynomial distributed lag (PDL) models.</p> <p>Results</p> <p>We observed a J-shaped exposure-response function only for 15-day average temperature and respiratory mortality in the warm period, with 21.3°C as the threshold temperature. All other exposure-response functions could be considered as linear. In the warm period, a 5°C increase of two-day average temperature was associated with a RR of 1.098 (95% confidence interval (95%CI): 1.057-1.140) for cardiovascular and 1.134 (95%CI: 1.050-1.224) for respiratory mortality; a 5°C decrease of 15-day average temperature was associated with a RR of 1.040 (95%CI: 0.990-1.093) for cardiovascular mortality. In the cold period, a 5°C increase of two-day average temperature was associated with a RR of 1.149 (95%CI: 1.078-1.224) for respiratory mortality; a 5°C decrease of 15-day average temperature was associated with a RR of 1.057 (95%CI: 1.022-1.094) for cardiovascular mortality. The effects remained robust after considering particles as additional confounders.</p> <p>Conclusions</p> <p>Both increases and decreases in air temperature are associated with an increased risk of cardiovascular mortality. The effects of heat were immediate while the ones of cold became predominant with longer time lags. Increases in air temperature are also associated with an immediate increased risk of respiratory mortality.</p
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