Variability in resistance-related enzyme activities in field populations of the tarnished plant bug, Lygus lineolaris

Widespread use of Bt crops for control of lepidopterous pests has reduced insecticide use and provided the tarnished plant bug the opportunity to become a serious pest on mid-South cotton. Organophosphate insecticides have predominantly been used against plant bugs in recent years due to the reduced efficacy of other insecticides. In this study, a biochemical approach was developed to survey enzymatic levels associated with organophosphate resistance levels in field populations of the tarnished plant bug. Forty-three populations were collected from the delta areas of Arkansas, Louisiana, and Mississippi. Three esterase substrates and one substrate each of glutathione S-transferase (GST) and acetylcholinesterase (AChE) were used to determine corresponding detoxification enzyme activities in different populations. Compared to a laboratory susceptible colony, increases up to 5.29-fold for esterase, 1.96-fold for GST, and 1.97-fold for AChE activities were detected in the field populations. In addition to the survey of enzyme activities among the populations, we also examined the susceptibility of major detoxification enzymes to several inhibitors which could be used in formulations to synergize insecticide toxicity against the target pests. As much as 52-76% of esterase, 72-98% of GST, and 93% of AChE activities were inhibited in vitro. Revealing variable esterase and GST activities among field populations may lead to a better understanding of resistance mechanisms in the tarnished plant bug. This study also reports effective suppression of detoxification enzymes which may be useful in future insecticide resistance management program for the tarnished plant bug and other Heteropteran pests on Bt crops.     

Autophagy-dependent anticancer immune responses induced by chemotherapeutic agents in mice

Antineoplastic chemotherapies are particularly efficient when they elicit immunogenic cell death, thus provoking an anticancer immune response. Here we demonstrate that autophagy, which is often disabled in cancer, is dispensable for chemotherapy-induced cell death but required for its immunogenicity. In response to chemotherapy, autophagy-competent, but not autophagy-deficient, cancers attracted dendritic cells and T lymphocytes into the tumor bed. Suppression of autophagy inhibited the release of adenosine triphosphate (ATP) from dying tumor cells. Conversely, inhibition of extracellular ATP-degrading enzymes increased pericellular ATP in autophagy-deficient tumors, reestablished the recruitment of immune cells, and restored chemotherapeutic responses but only in immunocompetent hosts. Thus, autophagy is essential for the immunogenic release of ATP from dying cells, and increased extracellular ATP concentrations improve the efficacy of antineoplastic chemotherapies when autophagy is disabled.     

Torsional oscillations of the sun

The sun's differential rotation has a cyclic pattern of change that is tightly correlated with the sunspot, or magnetic activity, cycle. This pattern can be described as a torsional oscillation, in which the solar rotation is periodically sped up or slowed down in certain zones of latitude while elsewhere the rotation remains essentially steady. The zones of anomalous rotation move on the sun in wavelike fashion, keeping pace with and flanking the zones of magnetic activity. It is uncertain whether this torsional oscillation is a globally coherent ringing of the sun or whether it is a local pattern caused by and causing local changes in the magnetic fields. In either case, it may be an important link in the connection between the rotation and the cycle that is widely believed to exist but is not yet understood.     

Lycopene degradation and isomerization kinetics during thermal processing of an olive oil/tomato emulsion

The stability of lycopene in an olive oil/tomato emulsion during thermal processing (80-140 °C) was studied. Initially, the degradation of total lycopene (all-E plus Z-forms) occurred quickly at temperatures above 100 °C. However, a nonzero plateau value, depending on the processing temperature, was attained after longer treatment times. Besides degradation, the isomerization of total-Z-lycopene as well as the individual isomerization of all-E-, 5-Z-, 9-Z-, and 13-Z-lycopene was studied in detail. After prolonged heating, the isomer conversion reached a temperature-dependent equilibrium state. The degradation of total lycopene and the isomerization could be described by a fractional conversion model. The temperature dependency of the corresponding reaction rate constants was quantified by the Arrhenius equation. The activation energy of degradation was estimated to be 28 kJ/mol, and the activation energy of overall (all-E and total-Z) isomerization was estimated to be 52 kJ/mol.     

Enteric campylobacter infection in gnotobiotic calves and lambs

Gnotobiotic calves and lambs were infected orally with Campylobacter jejuni, C coli or C hyointestinalis to assess pathogenicity. All animals were successfully colonised and excreted mucoid faeces but showed no other clinical signs. Campylobacters colonised the large intestine better than the small intestine, in which bacterial numbers decreased with time after infection. Campylobacters were found occasionally in the lumen of crypts in close proximity to epithelial cells and included in a mucus-like material. Lesions were mostly in the large intestine in calves whereas in lambs they were present in the ileum. In animals inoculated with C jejuni or C coli scattered crypt abscesses, focal inflammatory infiltrates in the lamina propria and goblet cell discharge were found. In lambs inoculated with C hyointestinalis only minor changes were found in the small intestine. Serum antibody response was either absent or present at a low level only from the 19th day after infection.     

Antiallergic effect of milk fermented with lactic acid bacteria in a murine animal model

The objective of this study was to assess the antiallergic effect of fermented milk prepared, respectively, with Streptococcus thermophilus MC, Lactobacillus acidophilus B, Lactobacillus bulgaricus Lb, L. bulgaricus 448, and Bifidobacterium longum B6. Female BALB/c mice fed fermented milk were immunized intraperitoneally with ovalbumin (OVA)/complete Freund's adjuvant (CFA) to evaluate the immune response by observing the secretion of cytokines IL-2, IL-4, and IFN-gamma and serum antibody IgE. The results showed that supplementation with lactic acid bacteria fermented milk did not significantly change the IL-2 spontaneous and OVA-stimulated secretions of splenocytes. However, both spontaneous and OVA-stimulated secretions of splenocytes from mice fed lactic acid bacteria fermented milk showed significantly (P < 0.05) lower levels of IL-4 (Th2 cytokine) than those from OVA/CFA-immunized mice fed non-fermented milk (OVA/CFA-milk group). The spontaneous secretion of IFN-gamma (Th1 cytokine) by splenocytes from mice fed L. bulgaricus 448 or L. bulgaricus Lb fermented milk significantly increased as compared to that from the OVA/CFA-milk group. The results showed that the ratios of IFN-gamma to IL-4 of both spontaneous and OVA-stimulated secretions in splenocytes from mice fed lactic acid bacteria fermented milk increased significantly as compared to that of PBS- or OVA/CFA-milk groups. The serum levels of OVA-specific IgE in fermented milk fed groups, especially the group fed S. thermophilus MC fermented milk, were significantly lower than those in the OVA/CFA-milk group through a 6 week feeding experiment. The results showed that milk fermented with lactic acid bacteria demonstrated in vivo antiallergic effects on OVA/CFA-immunized mice via increasing the secretion ratio of IFN-gamma/IL-4 (Th1/Th2) by splenocytes and decreasing the serum level of OVA-specific IgE.     

Temporal Trends of Trace Metals in Sediment and Invertebrates from Stormwater Management Ponds

Stormwater ponds are an increasingly common feature in urban landscapes. Because these ponds retain runoff and particulate-bound contaminants from impervious surfaces, organisms inhabiting stormwater ponds may be exposed to elevated metal levels in sediments. This study evaluated temporal changes in sediment and macroinvertebrate Cu, Pb and Zn over an eleven-year period with specific attention to land use in pond watersheds. Sediment and invertebrate metal levels were quantified using atomic absorption spectrophotometry (1993 samples) or inductively coupled plasma mass spectrometry (2003–2004 samples). Sediment trace element levels did not significantly change from 1993 to 2003-2004 with the exception of Zn in ponds receiving runoff from highways, which increased from a mean of 32 mg kg^?1 in 1993 to 344 mg kg^?1 in 2003–2004. Sediment Pb and Cu generally remained below published threshold effects concentrations (TEC) except for two instances of elevated Cu in 2003–2004. Zn remained below the TEC in 1993 but exceeded the TEC in six ponds in 2003–2004. Trace metal body burdens varied among invertebrate groups, and to a lesser extent among land uses, but in both cases this variation was a function of year. In general, trace element body burdens were more similar among invertebrate groups or land use or both during 2003–2004 when compared to levels in 1993. Our results suggest sediment and invertebrate trace metal levels are at steady state in these stormwater management ponds and that risk to organisms inhabiting these ponds does not vary as a function of pond age.     

Identifying priority areas for bioclimatic representation under climate change: a case study for Proteaceae in the Cape Floristic Region, South Africa

Biological reserves are established to protect natural resources and represent the diversity of environments found within a region. Unfortunately, many systems of protected areas do not proportionally capture the range of environmental conditions occupied by species and communities. Combinations of habitat loss and climate change may exacerbate these representational biases, and result in future distributions of environmental conditions that bare little resemblance to historic patterns. New protected areas need to be established to correct existing biases, and create conservation networks that remain representative despite climate change, habitat loss, and changes in species distributions. We demonstrate a new method to identify and prioritize habitat based on its value for improving bioclimatic representation. We assessed representation provided by existing protected areas for 301 Proteaceae species under historic and projected 2050 climate across the Cape Floristic Region in South Africa. The existing reserve system has relatively modest biases with respect to current species distributions and climate. However, if the system is not supplemented, protected areas in 2050 will capture an increasingly skewed sample of climatic conditions occupied by Proteaceae. These biases can be repaired through the systematic establishment of new protected areas, and many of the most valuable areas coincide with high priority ecosystem components and irreplaceable elements identified in the Cape Action for People and the Environmental conservation plan. Protecting these areas achieves nearly the best possible improvement in climatic representation while also meeting biodiversity representation goals.