Low Nutritional Conditions Research Articles

Natural malaria infection reduces starvation resistance of nutritionally stressed mosquitoes

In disease ecology, there is growing evidence that environmental quality interacts with parasite and host to determine host susceptibility to an infection. Most studies of malaria parasites have focused on the infection costs incurred by the hosts, and few have investigated the costs on mosquito vectors. The interplay between the environment, the vector and the parasite has therefore mostly been ignored and often relied on unnatural or allopatric Plasmodium/vector associations. Here, we investigated the effects of natural avian malaria infection on both fecundity and survival of field-caught female Culex pipiens mosquitoes, individually maintained in laboratory conditions. We manipulated environmental quality by providing mosquitoes with different concentrations of glucose-feeding solution prior to submitting them to a starvation challenge. We used molecular-based methods to assess mosquitoes' infection status. We found that mosquitoes infected with Plasmodium had lower starvation resistance than uninfected ones only under low nutritional conditions. The effect of nutritional stress varied with time, with the difference of starvation resistance between optimally and suboptimally fed mosquitoes increasing from spring to summer, as shown by a significant interaction between diet treatment and months of capture. Infected and uninfected mosquitoes had similar clutch size, indicating no effect of infection on fecundity. Overall, this study suggests that avian malaria vectors may suffer Plasmodium infection costs in their natural habitat, under certain environmental conditions. This may have major implications for disease transmission in the wild.

Significance evaluation of the effects of environmental factors on the lipid accumulation of Chlorella minutissima UTEX 2341 under low-nutrition heterotrophic condition

The effects of a variety of environmental factors on lipid accumulation of Chlorella minutissima UTEX 2341 under low-nutrition conditions were investigated. The growth of UTEX 2341 reached the exponential phase on the 1st day in low-nutrition medium. And the highest biomass productivity of 3.07 g L(-1) d(-1) was achieved on the 2nd day. The optimum pH and temperature for lipid accumulation were 6 and 20 °C respectively. 43.69 g L(-1) of NaCl and 0.11 mmol L(-1) of Fe(III) resulted in higher lipid content, analyzed by Design-Expert. And then under nitrogen starvation stress, the lipid content reached 22.84%. Meanwhile, the lipid yield was 2.5 g L(-1). The yield coefficient against carbon was 0.36 g g(-1), which was 4.68 times as much as that in OM medium. With the high proportion of C16 and C18 in the lipids, C. minutissima UTEX 2341 was proved to be a potential option for renewable biodiesel production.

Effects of parental and own early developmental conditions on the phenotype in zebra finches (Taeniopygia guttata)

The performance of an individual can be critically influenced by its experience early in life as well as trans-generationally by the conditions experienced by its parents. However, it remains unclear whether or not the early experience of parents and offspring interact with each other and adapt offspring when the parental and own early environmental conditions match. Here, zebra finches (Taeniopygia guttata) that had experienced either early low or high nutritional conditions raised their offspring under either matched or mismatched nutritional conditions. Parental and offspring early conditions both separately affected the offspring’s adult phenotype, but early conditions experienced by parents and offspring did not interact as predicted. Offspring that grew up under conditions matching those their parents had experienced did not do better than those that grew up in a mismatched environment. Thus, transgenerational effects remain a lifelong burden to the offspring acting in addition to the offspring’s own early life experience. The lack of evidence for adaptive programming to matching environmental conditions may result from non-predictive environments under natural conditions in such opportunistic breeders.

Use of an EZ-Tn5-based random mutagenesis system to create aZymomonas mobiliswith significant tolerance to heat stress and malnutrition

During ethanol production, the fermentation cells are always exposed to stresses like high temperature and low nutritional conditions, which affect their growth and productivity. Stress-tolerant strains with high ethanol yield are highly desirable. Therefore, a recombinant Zymomonas mobilis (Z. mobilis) designated as HYM was constructed by integrating three genes (yfdZ, metB, and Pfu-sHSP) into the genome of Z. mobilis CP4 (CP4) via Tn5 transposon in the present study. The yfdZ and metB genes from E. coli were used to decrease the nutritional requirement. The small heat shock protein gene (Pfu-sHSP) from Pyrococcus furiosus (P. furiosus) was used to increase the heat tolerance. The genomic integration of three genes confers on Z. mobilis the ability to grow in simple chemical defined medium without the addition of amino acid. The HYM not only demonstrated the high tolerance to unfavorable lower nutrition stresses but also the capability of converting glucose to ethanol with high yield at higher temperature. What is more, these genetic characteristics were stable up to 100 generations on nonselective medium. The effects of glucose concentration, fermentation temperature, and initial pH on ethanol production of the mutant strain HYM were optimized using a Box-Behnken design (BBD) experiment. The integration of three genes led to a significant increase in ethanol production by 9 % compared with its original Z. mobilis counterpart. The maximum ethanol production of HYM was as high as 105 g/l.

Use of a Tn5-based transposon system to create a cost-effective Zymomonas mobilis for ethanol production from lignocelluloses

BackgroundCurrent methods of ethanol production from lignocelluloses generate a mixture of sugars, primarily glucose and xylose; the fermentation cells are always exposed to stresses like high temperature and low nutritional conditions that affect their growth and productivity. Stress-tolerant strains capable of using both glucose and xylose to produce ethanol with high yield are highly desirable.ResultsA recombinant Zymomonas mobilis (Z. mobilis) designated as HYMX was constructed by integrating seven genes (Pfu-sHSP, yfdZ, metB, xylA, xylB, tktA and talB) into the genome of Z. mobilis CP4 (CP4) via Tn5 transposon in the present study. The small heat shock protein gene (Pfu-sHSP) from Pyrococcus furious (P. furious) was used to increase the heat-tolerance, the yfdZ and metB genes from E. coli were used to decrease the nutritional requirement. To overcome the bottleneck of CP4 being unable to use pentose, xylose catabolic genes (xylA, xylB, tktA and talB) from E. coli were integrated into CP4 also for construction of the xylose utilizing metabolic pathway.ConclusionsThe genomic integration confers on Z. mobilis the ability to grow in medium containing xylose as the only carbon source, and to grow in simple chemical defined medium without addition of amino acid. The HYMX demonstrated not only the high tolerance to unfavorable stresses like high temperature and low nutrient, but also the capability of converting both glucose and xylose to ethanol with high yield at high temperature. What’s more, these genetic characteristics were stable up to 100 generations on nonselective medium. Although significant improvements were achieved, yeast extract is needed for ethanol production.

New Perspectives on Ancient Granulomas

EDITORIAL article Front. Immunol., 15 November 2013Sec. Inflammation Volume 4 - 2013 | https://doi.org/10.3389/fimmu.2013.00345

Spatial management of marine resources can enhance the recovery of predators and avoid local depletion of forage fish

AbstractThe eastern Baltic cod stock has recently started to recover, after two decades of severe depletion, however with unexpected side effects. The stock has not re‐occupied its former wide distribution range, but remains concentrated in a limited area in the southern Baltic Sea. The biomass of forage fish, i.e., sprat and herring, is historic low in this area, which in combination with increasing cod stock results in locally high predation mortality of forage fish and cannibalism of cod. In line with low prey availability, body weight and nutritional condition of cod drastically declined. In the southern Baltic Sea, cod competes with pelagic fisheries for the limited resources of sprat and herring, while the largest biomass of these species is currently found outside the distribution range of cod. Accounting for spatial overlap between species is crucial in developing ecosystem based fisheries management to enhance the recovery of predator stocks.

Antiausterity Agents from Uvaria dac and Their Preferential Cytotoxic Activity against Human Pancreatic Cancer Cell Lines in a Nutrient-Deprived Condition

Human pancreatic cancer cell lines are known for their inherent tolerance to nutrition starvation, which enables them to survive under a hypovascular (austerity) tumor microenvironment. The search for agents that preferentially retard the survival of cancer cells under low nutrition conditions (antiausterity agent) is a novel approach to anticancer drug discovery. In this study, it was found that a dichloromethane extract of the stem of Uvaria dac preferentially inhibited PANC-1 human pancreatic cancer cells survival under nutrition-deprived conditions at a concentration of 10 μg/mL. Workup of this bioactive extract led to the discovery of (+)-grandifloracin (8) as a potent antiausterity agent as evaluated in a panel of four human pancreatic cancer cell lines, PANC-1 (PC(50), 14.5 μM), PSN-1 (PC(50), 32.6 μM), MIA PaCa-2 (PC(50), 17.5 μM), and KLM-1 (32.7 μM). (+)-Grandifloracin (8) has been isolated from a natural source for the first time. Its absolute stereochemistry was established by single-crystal X-ray crystallography and circular dichroism spectroscopic analysis. In addition to this, seven other new highly oxygenated cyclohexene derivatives, named uvaridacanes A (1) and B (2), uvaridacols A-D (3, 4, 6, 7), and uvaridapoxide A (5), were also isolated and structurally characterized.

Plasticity in the expression of direct and indirect defence traits of young plants of Mallotus japonicus in relation to soil nutritional conditions

Although soil nutrients can influence the defence strategy of plants that have multiple defence traits, to date, there have been few studies to examine this. To evaluate the effect of soil nutrients on multiple plant defences, we cultivated Mallotus japonicus under three soil nutritional conditions in the field, and experimentally examined the expression of a physical defence trait (trichomes), chemical traits (pellucid dots), and biotic traits (extrafloral nectaries (EFNs) and pearl bodies) of the plants, and the number of ants visiting them. Under the low soil nutritional condition, plants strongly expressed the physical defence by trichomes and chemical defence by pellucid dots, meaning that the young plants adopted direct defences under the poor soil nutritional condition. Under the high soil nutritional condition, in contrast, the plants strongly expressed the indirect defence traits. They produced abundant EFNs and pearl bodies, and attracted many ants. These results suggest that young plants of M. japonicus use different defence modes in response to different soil nutritional conditions.

A study on low performance status cases of pulmonary tuberculosis in the elderly

The subjects consisted of 42 patients aged over 60 years, whose performance status (PS) was grade 3 or 4, and who had been admitted for pulmonary tuberculosis at National Chiba-Higashi Hospital between 1997 and 1998. The average age (+/- SD) of the 34 men and 8 women was 77.6 (+/- 8.5) years (range, 60-91 years). The mean stay in the hospital of the improved patients was 166.6 days (range, 57-303 days), and the mean survival period from admission to death was 43.4 days (range, 2-179 days in died patients). On admission to our hospital, 26 cases were sputum smear positive, 8 cases were smear negative and culture positive, and 8 were negative both on smear and culture. The cavity was observed in 30 cases (71.4%) on the chest X-ray. The laboratory data on admission revealed low nutritional condition. The mean serum total protein, albumin, and cholesterol level on admission were 6.2 (+/- 0.82) g/dl, 2.7 (+/- 0.62) g/dl, and 143.0 (+/- 41.9) mg/dl. Most of the patients had a difficulty in taking foods, and 20 cases (47.6%) were performed parenteral nutrition by central venous catheter. 23 cases (54.8%) received oxygen therapy by facial mask or nasal tube. The most common cause of low PS on admission was pulmonary tuberculosis in 14 cases (33.3%), followed by cerebrovascular diseases in 11 cases, and orthopedic disease in 8 cases. The proportion of patients whose cause of low PS was not due to lung tuberculosis increased with age. Observing the mortality by the route of administration of antituberculosis medications on admission, 19 (55.9%) of 34 cases who could take drugs per oral route died. One (50.0%) of 2 cases who were administered drugs through gastric tube died, and all (100.0%) of 5 cases who could not take drugs per oral route and were injected isoniazid and streptomycin died. One case who could not administer any drug died. 16 cases improved and 26 cases died, of whom the most common cause of death was pulmonary tuberculosis in 11 cases (42.3%), followed by bacterial pneumonia in 5 cases, and cerebrovascular disease in 3 cases. The mortality by the PS on admission were as follows: 10 (47.6%) of 21 cases with PS 3 died. 16 (76.2%) of 21 cases with PS 4 died. 16 (6.4%) of 249 cases aged over 60 years with PS 0, 1 or 2, and were admitted for pulmonary tuberculosis at the same hospital during the same period died. This study confirms that the prognosis of low performance status patients of pulmonary tuberculosis in the elderly was significantly poor. We have to detect tuberculosis patients in the early stage, and give them antituberculosis medications per oral route as far as possible.

Size Matters (but So Does Time), and It's OK to Be Different

In this issue of Developmental Cell, Layalle et al. reveal new insights into how nutrition controls body size in Drosophila. Nutrition specifically affects the activity of target of rapamycin (TOR) in the prothoracic gland. Under low-nutrition conditions, TOR suppresses ecdysone secretion--which otherwise terminates larval development--thereby prolonging growth and allowing larvae to still attain a near-normal body size.

Population development and breeding success of Grey Heron Ardea cinerea in South-eastern Norway

The Grey Heron Ardea cinerea was first found breeding in Østfold county, SE Norway, in the early 1970s, most probably as a result of population growth in Sweden. The population of the county increased until the late 1980s, when approx. 40 pairs bred. A count in 2005 showed that at least 166 pairs were breeding in six colonies. In Follo, Akershus there were found two colonies with 13 pairs. Three more colonies were found in Østfold in 2006. The number breeding in the colonies was lower in 2006 than in the previous year (a 38 % reduction), probably due to the cold winter of 2005/2006. The Grey Heron still breeds in several colonies established in the 1980s. This study of nesting sites in Østfold shows that colonies are mostly placed on south-facing slopes, and the colonies have a buffer of protective trees. They are often placed close to roads and habitation. Human disturbance does not seem to be a problem, with one main exception: logging. Breeding success was studied in four colonies, two of them newly established and two with a known history back to the 1980s. The numbers of chicks were counted at a specific period in the breeding season. The Grey Heron begins incubating after the first egg is laid, and among young chicks there are weight differences. Siblicide is widespread, and is reckoned as an indicator of low nutritional conditions. A large weight difference among the chicks in the brood could indicate a high probability for siblicide. Sixty-four chicks were weighed in 19 nests, and a comparison was made between pairs in colonies of different age and size. The results show that the number of chicks, or breeding success, measured at a specific period in the season, was higher in small and new colonies compared to the larger and well-established ones. But the average weight of chicks was greater in the oldest and largest of the two colonies. This could indicate a lower tendency to siblicide, but is more probably a result of an earlier breeding start in the oldest colony. The chicks were on average fewer and larger, and the pairs were probably in a later stage in the breeding process. The results based upon counts in the nesting period do not support the hypothesis that the Grey Heron gains a higher breeding success in larger and well-established colonies than in smaller and newer ones. But an early start and fledging could increase juvenile survival to the next breeding season. The importance of an early breeding start could be a major explanation for colony fidelity.

Nutritional condition of metamorphosing sole: spatial and temporal analyses

Sole Solea solea larvae were collected during five cruises in the Bay of Biscay in 1992 and 1993. The larval growth rate, triacylgycerol (TAG) and sterol (ST) content, and the width of the marginal otolith increments were determined on the same individual larva as indicators of nutritional condition. The TAG content increased during the ontogenetic larval development up to an elevated value corresponding to the end of metamorphosis. During metamorphosis, sole larvae continued to accumulate TAG and to increase in length. Seasonal and yearly variations of growth and nutritional condition of sole larvae at the onset of metamorphosis were more important than spatial variations. Analysis of larval growth showed that, during each cruise, the faster growing larvae were generally those with the highest TAG content (and TAG : ST ratio). In 1993, larvae began to metamorphose earlier and their growth (both larval growth and recent growth) were significantly higher than in 1992. Their relatively low nutritional condition, however, seemed to be the result of a low accumulation of TAG. Sole metamorphosis occurs without growth arrest and the majority of the larvae during this phase are judged to be in good nutritional condition (TAG : ST ratio > 1). In the Bay of Biscay, metamorphosis does not seem to be a critical period in the life cycle of the sole. It is suggested that larvae originating from different cohorts probably have the same chance of survival during or just after metamorphosis when they enter the benthic environment.

Cod egg characteristics and viability in relation to low temperature and maternal nutritional condition

In 1995 and 1996, groups of female cod (Gadus morhua) of varying nutritional condition and maturing at different temperatures were used to investigate relationships between female condition, egg production, egg characteristics, and viability. Over the two years, egg samples from every batch spawned by 34 females were analyzed for egg diameter, dry mass, and energy content. In addition, 51 egg batches from 24 females (ca. 2 egg batches female −1 yr −1 ) were used to monitor development rate and hatching success. The weighted mean egg dry mass was positively correlated (p<0.05) to the females' pre-spawning condition in 1996. In 1995 this positive correlation was not observed for females at ∼2°C during maturation. For both years, the decline in the mean egg dry mass per batch throughout spawning was correlated (p<0.05) with the females' post-spawning energy reserves. However, no trend in the total egg dry mass per batch during the sequence of spawning was observed. Thus, the total energy investment per batch remained stable throughout spawning and was not influenced by the depletion of the females' energy reserves. In 1996, high hatching successes were observed only for egg batches from females in high pre-spawning condition. However, egg size and dry mass showed no correlation with survival rate or hatching success in either year.

Ökologische Aspekte der Ausbreitung von Bidens frondosa L. in Mitteleuropa. Verdrängt er Bidens tripartita L.?

Sometimes it was supposed, that the invading species of North American origin Bidens frondosa removes the indigenous B. tripartita. The aim of this study was to look for some evidence. Comparing germination pattern, growth, dry matter production, reproductive features, and architecture of both species it is obvious that B. frondosa is able to outcompete B. tripartita. In D e W it -replacement series it can be shown that B. tripartita is supressed under high, medium and low nutritional conditions.

Characteristics of generic composition of aerobic heterotrophic bacteria in periphyton at an oligotrophic region in the Tamagawa River.

The bacterial generic composition in the Periphyton at an oligotrophic region in the Tamagawa River was studied during different seasons and in different colored Periphyton. Shannon's diversity index of bacterial generic composition was highly correlated to the amount of chlorophyll in the periphyton. In the bacterial generic composition of brownish periphyton mainly composed of Bacillariophyta, yellowish brown Cytophaga sp. (represented as Cytophaga (yb)) was the predominant bacterial group in summer, and red Flavobacterium sp. (Flavobacterium (r)) in winter and spring. Greenish periphyton contained Ulothrix zonata in addition to Bacillariophyta, small yellow Flavobacterium sp. (Flavobacterium (sy)) was predominant. Cytophaga (yb) was accompanied by the exponential growth phase of Cymbella sp., and Flavobacterium (r) predominated only under low nutritional conditions when other bacterial groups could not grow. Flavobacterium (sy) was observed with Ulothrix zonata and Navicula spp., but the appearance of this group was paralleled by an increase in the total bacterial number. As a result, it predominated when a larger number of bacteria were present. Bacterial generic groups at the river region studied were divided into three categories: (i) those groups existing primarily in running water, (ii) those mainly inhabiting the periphyton, and (iii) those consistently isolated from both periphyton and running water.

An interaction between season of calving and nutrition on the resumption of ovarian cycles in post-partum beef cattle.

Angus cows were first mated at approximately 27 months of age in 2 herds, calving 21 July to 15 September (Group E) or 9 September to 30 October (Group L). The cows were fed a high (H) or medium (M) plane of nutrition for 55 days before and 40 days after calving. There was a mean liveweight difference of 35 kg between cows in Groups EH + LH and Groups EM + LM immediately after calving and at 40 days after calving. Immediately after calving cows in Groups EH + EM were 11 kg heavier than cows in Groups LH + LM, but there was no difference at 40 days after calving. There was a significant interaction between calving time and nutrition in the return of cyclic ovarian function assessed from both interval to first oestrus and first elevated progesterone concentration. Mean intervals from calving to first oestrus were 66.7, 82.7, 56.7 and 62.3 days in Groups EH, EM, LH and LM respectively. These data demonstrate that season of calving influences resumption of ovarian cycles even at a constant high plane of nutrition and that season of calving interacts with nutrition such that effects of season are more likely to be expressed under conditions of low nutrition.

Virus-like particles in the aquatic fungus, Rhizidiomyces

Isometric virus-like particles (VLPs), 60 nm in diameter, have been observed by electron microscopy in eight isolates of thermal-shocked Rhizidiomyces, a zoosporic, unicellular member of the Hyphochytridiales. VLP pathogenesis was observed in all fungal developmental stages from the zoospores to the mature sporangia. Paracrystalline structures associated with mitochondria preceded VLP occurrence in multinucleate sporangia. Particles appeared first in the intact nucleus, and subsequently VLPs completely replaced the nucleus and cytoplasm of the fungal host. Cell wall breakdown followed with release of VLPs into the medium. Approximately 50% of each fungal isolate was destroyed by the VLPs under stress conditions of heat, low nutrition, or aging. However, sufficient numbers of zoospores were capable of maturing into sporangia which produced zoospores to maintain the isolates in culture. After cloning 10 generations of zoospores, VLPs could still be produced in the offspring, thus indicating vertical transmission of the VLPs from generation to generation.

A body composition model for predicting beef animal growth

Two beef animal growth computer simulations were compared as to the effects of altering feed energy density. Steers of varying initial degrees of fatness were evaluated. The BEEF-NC114 model used NRC regression equations to predict growth while the BEEF-S156 model used physiological age and body components. Otherwise, the models were essentially identical. On average, the predictions of both models were reasonably close to each other. However, the BEEF-S156 model was more sensitive to extreme conditions of high or low nutrition.

DIFFERENTIAL RESPONSE OF TIMOTHY CLONAL LINES AND CULTIVARS TO SOIL TEMPERATURE, MOISTURE AND FERTILITY

Six clonal stocks of timothy (Phleum pratense L.) were tested under different soil environmental conditions in the greenhouse using three soil temperatures, two moistures and four nutritional levels. The average herbage yields from the various environmental conditions showed that the four parental selections of ’Champ’ were in the order of S-5 = S-9 &gt; S-2 = S-6. Under high nutrition (N1P1) and soil moisture (75% available water) S-5, S-9, and Drummond yielded the largest at a soil temperature of 10 C, S-5 and S-9 yielded the most at 20 C, and S-2 the highest under a soil temperature of 27 C (day) and 20 C (night). Under low nutrition the differences among the selections were small. Under high nutrition, a change in temperature from 10 to 20 C increased late seasonal growth but had little effect on early growth, with an overall Q10 = 0.23, while under low nutrition, a similar change in temperature increased both early and later growth with a mean Q10 = 1.83. There was a delay in the optimum rate of regrowth with increase in temperature (10, 20, to 27/20 C). The S-5 tillered well at the lower temperatures, S-6 at the higher temperatures, and S-9, at all three temperatures.The yield potential of Champ appears to be similar to the two cultivars under low soil temperature and nutritional condition but greater than them under higher soil temperatures, nutrition and moisture.