Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 ...concentrations may affect irrigation requirements in the Mediterranean region by 2080–2090. Future demographic change and technological improvements in irrigation systems are taken into account, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL (Lund–Potsdam–Jena managed Land) after an extensive development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries such as Syria, Egypt and Turkey have a higher savings potential than others. Currently some crops, especially sugar cane and agricultural trees, consume on average more irrigation water per hectare than annual crops. Different crops show different magnitudes of changes in net irrigation requirements due to climate change, the increases being most pronounced in agricultural trees. The Mediterranean area as a whole may face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (4 and 18 % with 2 °C global warming combined with the full CO2-fertilization effect and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the southern and eastern Mediterranean. However, improved irrigation technologies and conveyance systems have a large water saving potential, especially in the eastern Mediterranean, and may be able to compensate to some degree for the increases due to climate change and population growth. Both subregions would need around 35 % more water than today if they implement some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect. Nevertheless, water scarcity may pose further challenges to the agricultural sector: Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain have a high risk of not being able to sustainably meet future irrigation water requirements in some scenarios. The results presented in this study point to the necessity of performing further research on climate-friendly agro-ecosystems in order to assess, on the one hand, their degree of resilience to climate shocks and, on the other hand, their adaptation potential when confronted with higher temperatures and changes in water availability.
This study compares, spatially explicitly and at global scale, per capita water availability and water requirements for food production presently (1971–2000) and in the future given climate and ...population change (2070–99). A vegetation and hydrology model Lund–Potsdam–Jena managed Land (LPJmL) was used to calculate green and blue water availability per capita, water requirements to produce a balanced diet representing a benchmark for hunger alleviation 3000 kilocalories per capita per day (1 kilocalorie = 4184 joules), here assumed to consist of 80% vegetal food and 20% animal products, and a new water scarcity indicator that relates the two at country scale. A country was considered water-scarce if its water availability fell below the water requirement for the specified diet, which is presently the case especially in North and East Africa and in southwestern Asia. Under climate (derived from 17 general circulation models) and population change (A2 and B1 emissions and population scenarios), water availability per person will most probably diminish in many regions. At the same time the calorie-specific water requirements tend to decrease, due mainly to the positive effect of rising atmospheric CO₂ concentration on crop water productivity—which, however, is very uncertain to be fully realized in most regions. As a net effect of climate, CO₂, and population change, water scarcity will become aggravated in many countries, and a number of additional countries are at risk of losing their present capacity to produce a balanced diet for their inhabitants.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of ...schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
Erythroblast maturation in mammals is dependent on organelle clearance throughout terminal erythropoiesis. We studied the role of the outer mitochondrial membrane protein voltage-dependent anion ...channel-1 (VDAC1) in human terminal erythropoiesis. We show that short hairpin (shRNA)-mediated downregulation of VDAC1 accelerates erythroblast maturation. Thereafter, erythroblasts are blocked at the orthochromatic stage, exhibiting a significant decreased level of enucleation, concomitant with an increased cell death. We demonstrate that mitochondria clearance starts at the transition from basophilic to polychromatic erythroblast, and that VDAC1 downregulation induces the mitochondrial retention. In damaged mitochondria from non-erythroid cells, VDAC1 was identified as a target for Parkin-mediated ubiquitination to recruit the phagophore. Here, we showed that VDAC1 is involved in phagophore's membrane recruitment regulating selective mitophagy of still functional mitochondria from human erythroblasts. These findings demonstrate for the first time a crucial role for VDAC1 in human erythroblast terminal differentiation, regulating mitochondria clearance.
Multivesicular bodies (MVBs) are membranous structures within 60–100 nm diameter vesicles accumulate. MVBs are generated after invagination and pinching off of the endosomal membrane in the lumen of ...the vacuole. In certain cell types, fusion of MVBs with the plasma membrane results in the release of the internal vesicles called exosomes. In this report we have examined how an increase in cytosolic calcium affects the development of MVBs and exosome release in K562 cells overexpressing GFP‐Rab11 wt or its mutants. In cells overexpressing the Rab11Q70 L mutant or Rab11 wt, an increase in the cytosolic calcium concentration induced by monensin caused a marked enlargement of the MVBs. This effect was abrogated by the membrane permeant calcium chelator BAPTA‐AM. We also examined the behavior of MVBs in living cells by time lapse confocal microscopy. Many MVBs, decorated by wt or Q70L mutant GFP‐Rab11, were docked and ready to fuse in the presence of a calcium chelator. This observation suggests that Rab11 is acting in the tethering/docking of MVBs to promote homotypic fusion, but that the final fusion reaction requires the presence of calcium. Additionally, a rise in intracellular calcium concentration enhanced exosome secretion in Rab11 wt overexpressing cells and reversed the inhibition of the mutants. The results suggest that both Rab11 and calcium are involved in the homotypic fusion of MVBs.
Staphylococcus aureus is a pathogen that causes serious infectious diseases eventually leading to septic and toxic shock. Classically S. aureus has been considered an extracellular pathogen, but ...cumulative evidence indicates that it invades cells and replicates intracellularly leading to staphylococcal persistence and chronic disease. It has been previously shown that this pathogen localizes to LC3-labeled compartments and subverts the autophagy pathway. One of the key features of S. aureus infection is the production of a series of virulence factors, including secreted enzymes and toxins. In the present report we present evidence that the pore-forming toxin α-hemolysin (Hla) is a S. aureus secreted factor which participates in the activation of the autophagic pathway. In addition, our results indicate that although the toxin elicits an autophagic response this pathway is dysfunctional as indicated by the accumulation of the LC3-II form in cell lysates obtained from intoxicated cells. In addition, not only the purified Hla toxin but also the toxin-secreting pathogen prevented the maturation of autophagosome. Interestingly, in cells infected with the wild type strain of S. aureus the bacteria-containing compartments which recruited LC3 onto the limiting membrane did not accumulate the acidotropic probe LysoTracker. In contrast, those phagosomes containing the Hla(-) mutant (unable to produce the toxin) localized in an acidic compartment unlabeled by LC3. These results suggest that the LC3 protein is recruited only to those damaged vacuoles (i. e. perforated by the toxin), perhaps as an attempt to protect the cells. Furthermore, we have demonstrated that the toxin-dependent activation of autophagy although it is regulated by calcium and requires Atg5 is independent of both PI3Kinase activity and Beclin 1 suggesting the involvement of a non-canonical autophagy pathway.
Background
The number of people with an enteral tube (ET) living at home is increasing globally and services to support them to manage this complex and life‐changing intervention vary across regions. ...The present study aimed to gain an understanding of the experiences of people living at home with an ET and their carers, as well as to explore their views of supporting services and ET‐related hospital admissions.
Methods
A qualitative inductive descriptive design was employed. Semi‐structured, face‐to‐face interviews with a purposive sample of people with an ET living at home and carers were undertaken. Interviews were transcribed, initial codes were assigned for salient constructs, and these were then grouped and developed into themes and sub‐themes.
Results
Nineteen people with ETs and 15 carers of people with ETs were interviewed. Five themes were generated: home better than hospital, feelings about the tube, living with the tube, help when you need it and cost for health service. Participants indicated the ET significantly influenced daily life. Participants described becoming used to coping with the ET at home over time and developing strategies to manage problems, avoid hospital admission and reduce resource waste. Variation in supporting services was described.
Conclusions
People with ETs and their carers need considerable support from knowledgeable, responsive healthcare practitioners during the weeks following initial placement of the ET. Twenty‐four hour services to support people with ETs should be designed in partnership with the aim of reducing burden, negative experience, waste and hospital admissions. National frameworks for home enteral nutrition could set the standard for support for people with ETs.
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