פרסומים

Stomatal oscillations are cyclic opening and closing of stomata, presumed to initiate from hydraulic mismatch between leaf water supply and transpiration rate. To test this assumption, mismatches between water supply and transpiration were induced using manipulations of vapour pressure deficit (VPD) and light spectrum in banana (Musa acuminata). Simultaneous measurements of gas exchange with changes in leaf turgor pressure were used to describe the hydraulic mismatches. An increase of VPD above a certain threshold caused stomatal oscillations with variable amplitudes. Oscillations in leaf turgor pressure were synchronized with stomatal oscillations and balanced only when transpiration equaled water supply. Surprisingly, changing the light spectrum from red and blue to red alone at constant VPD also induced stomatal oscillations – while the addition of blue (10%) to red light only ended oscillations. Blue light is known to induce stomatal opening and thus should increase the hydraulic mismatch, reduce the VPD threshold for oscillations and increase the oscillation amplitude. Unexpectedly, blue light reduced oscillation amplitude, increased VPD threshold and reduced turgor pressure loss. These results suggest that additionally, to the known effect of blue light on the hydroactive opening response of stomata, it can also effect stomatal movement by increased xylem–epidermis water supply. © 2017 John Wiley & Sons Ltd

Epidemiologic studies have demonstrated an association of elevated plasma homocysteine levels with greater bone resorption and fracture risk. Vitamins B , B , and folic acid are cofactors in homocysteine metabolism, and supplementation with B vitamins is effective in lowering homocysteine levels in humans. However, randomized trials of supplemental B vitamins for reduction of fracture risk have been limited. Therefore, we performed an ancillary study to the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS), a large randomized trial of women with preexisting cardiovascular disease or three or more coronary risk factors, to test whether a daily B vitamin intervention including folic acid (2.5 mg/day), vitamin B (50 mg/day), and vitamin B (1 mg/day) reduces nonspine fracture risk over 7.3 years of treatment and follow-up. Among 4810 women, we confirmed 349 nonspine fracture cases by centralized review of medical records. In a substudy of 300 women (150 in treatment group and 150 controls) with paired plasma samples at randomization and follow-up (7.3 years later), we measured two bone turnover markers, including C-terminal cross-linking telopeptide of type I collagen (CTX) and intact type I procollagen N-propeptide (P1NP). In Cox proportional hazards models based on intention-to-treat, we found no significant effects of B vitamin supplementation on nonspine fracture risk (relative hazard = 1.08; 95% confidence interval, 0.88 to 1.34). In a nested case-cohort analysis, there were no significant effects of B vitamins on fracture risk among women with elevated plasma homocysteine levels, or low levels of vitamins B or B , or folate at baseline. Furthermore, treatment with B vitamins had no effect on change in markers of bone turnover. We found no evidence that daily supplementation with B vitamins reduces fracture risk or rates of bone metabolism in middle-aged and older women at high risk of cardiovascular disease. © 2017 American Society for Bone and Mineral Research.

Mixed diets of prey and plant-provided foods, such as pollen, have been shown to benefit a wide range of arthropods. However, diet shifting between these two very different food sources remains poorly understood. We hypothesized that previous diet should influence subsequent time allocation between prey and plant food types; to reach a balanced diet, consumers are expected to allocate more time to resources previously lacking in their diet. We tested this hypothesis by observing the foraging choices of larvae of two omnivorous coccinellid species: Coccinella septempunctata L. and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), following a diet history of prey, pollen or a mixed diet of both food types. Results showed an asymmetrical tendency of C. septempunctata larvae to complement their previous diet with unfamiliar food: larvae allocated more time to pollen feeding, but not to prey, when each of the foods was previously absent from their diet. Study results have important implications for the use of plant-provided food supplements to enhance biological control by these omnivorous consumers.

Among the components of the female reproductive tract, the ovarian pool of follicles and their enclosed oocytes are highly sensitive to hyperthermia. Heat-induced alterations in small antral follicles can be expressed later as compromised maturation and developmental capacity of the ovulating oocyte. This review summarizes the most up-to-date information on the effects of heat stress on the oocyte with an emphasis on unclear points and open questions, some of which might involve new research directions, for instance, whether preantral follicles are heat resistant. The review focuses on the follicle-enclosed oocytes, provides new insights into the cellular and molecular responses of the oocyte to elevated temperature, points out the role of the follicle microenvironment, and discusses some mechanisms that might underlie oocyte impairment. Mechanisms include nuclear and cytoplasmic maturation, mitochondrial function, apoptotic pathways, and oxidative stress. Understanding the mechanism by which heat stress compromises fertility might enable development of new strategies to mitigate its effects.Among the components of the female reproductive tract, the ovarian pool of follicles and their enclosed oocytes are highly sensitive to hyperthermia. Heat-induced alterations in small antral follicles can be expressed later as compromised maturation and developmental capacity of the ovulating oocyte. This review summarizes the most up-to-date information on the effects of heat stress on the oocyte with an emphasis on unclear points and open questions, some of which might involve new research directions, for instance, whether preantral follicles are heat resistant. The review focuses on the follicle-enclosed oocytes, provides new insights into the cellular and molecular responses of the oocyte to elevated temperature, points out the role of the follicle microenvironment, and discusses some mechanisms that might underlie oocyte impairment. Mechanisms include nuclear and cytoplasmic maturation, mitochondrial function, apoptotic pathways, and oxidative stress. Understanding the mechanism by which heat stress compromises fertility might enable development of new strategies to mitigate its effects.

In 2009 Laron amendment was implemented. Its purpose was to change disabled workers incentives by reforming the formula related to work allowances. We checked the impact of this amendment by analyzing workers behavior after five years of implementation. By comparing disabled workers to workers of similar background that did not receive the allowance we answer to the following questions: what was the impact of Laron ammendment on their work supply? what are the characteristics of workers that substantially reacted to Laron ammendment? 

To increase colonoscopy competence in ambiguous situations (e.g. the existence of flat polyps), an explicit in situ (at real time) diagnosis at the molecular level is required. We have previously shown that the affinity of fluorescent cationic polyacrylamide (Flu-CPAA) to malignant regions in the colon mucosa can be improved by conjugating the recognition peptide EPPT1 to the polymer backbone (to form Flu-CPAA-Pep). Using another recognition peptide, namely VRPMPLQ, we elucidated in the present study the effect of linker type and conjugating methods on Flu-CPAA-VRPMPLQ cytotoxicity and on its affinity to cell lines as well as human colorectal cancer (CRC) biopsies. In order to derive the relationship between the response variable and the experimental factors in a minimal set of experiments, a computerized statistical design of experiment (DoE) strategy was implemented. Data were collected in a six-factor factorial design to study the effect of experimental factors (independent variables) on the ability of the Flu-CPAA polymers to bind specifically to the colon cancer cell lines or the human biopsies (the response). It was found that the presence of VRPMPLQ on the Flu-CPAA improved the polymer's affinity to the human CRC biopsies and to the colon cancer cell lines representing stage B in the Duke severity staging system. The cytotoxicity of Flu-CPAA with high charge density was reduced after conjugated with VRPMPLQ. The replacement of Ahx linker by PEG linker of similar length did not affect the affinity to the human biopsies, nor did it affect cytotoxicity. However, elongating the PEG linker reduced the in vitro affinity to the colon cancer cell lines and to human CRC biopsies. Changing the conjugation method from condensation (amide bond formation) to the click conjugation method did not affect the affinity properties of the polymers. It did reduce, however, the polymer cytotoxicity. We suggest that Flu-CPAA-Pep, with the VRPMPLQ peptide as a recognition moiety, could serve for early diagnosis and screening of CRC patients during endoscopic procedures.

The lipophilic phytocannabinoids cannabidiol (CBD) and $Δ$(9)-tetrahydrocannabinol (THC) show therapeutic efficacy in various medical conditions. Both molecules are poorly water soluble and subjected to extensive first pass metabolism in the gastrointestinal tract, leading to a limited oral bioavailability of approximately 9%. We have developed an advanced lipid based Self-Emulsifying Drug Delivery System termed Advanced Pro-NanoLiposphere (PNL) pre-concentrate. The PNL is composed of lipid and emulsifying excipients of GRAS status and are known to increase solubility and reduce Phase I metabolism of lipophilic active compounds. Advanced PNLs are PNLs with an incorporated natural absorption enhancers. These molecules are natural alkaloids and phenolic compounds which were reported to inhibit certain phase I and phase II metabolism processes. Here we use piperine, curcumin and resveratrol to formulate the Advanced-PNL formulations. Consequently, we have explored the utility of these Advanced-PNLs on CBD and THC oral bioavailability. Oral administration of CBD-piperine-PNL resulted in 6-fold increase in AUC compared to CBD solution, proving to be the most effective of the screened formulations. The same trend was found in pharmacokinetic experiments of THC-piperine-PNL which resulted in a 9.3-fold increase in AUC as compared to THC solution. Our Piperine-PNL can be used as a platform for synchronized delivery of piperine and CBD or THC to the enterocyte site. This co-localization provides an increase in CBD and THC bioavailability by its effect at the pre-enterocyte and the enterocyte levels of the absorption process. The extra augmentation in the absorption of CBD and THC by incorporating piperine into PNL is attributed to the inhibition of Phase I and phase II metabolism by piperine in addition to the Phase I metabolism and P-gp inhibition by PNL. These novel results pave the way to utilize piperine-PNL delivery system for other poorly soluble, highly metabolized compounds that currently cannot be administered orally.

Atrazine (ATZ), one of the most extensively used herbicides, is considered a ubiquitous environmental contaminant. ATZ is a known endocrine disruptor, and deleterious effects on reproductive function have been shown, even at low, ecologically relevant doses (0.1–3μg/L). Once it enters the body, ATZ is metabolized to various metabolites, which are further detected in the urine, serum and tissues. In mammals, the major ATZ metabolite is diaminochlorotriazine (DACT). The current study focuses on direct effects of low doses of ATZ and DACT on bovine sperm isolated from ejaculates or epididymis compartments (head, body and tail). Sperm were incubated under capacitation conditions with or without 0.1–10μM ATZ or 1–100μM DACT. The integrity and functionality of sperm membranes (plasma, acrosomal and mitochondrial) were examined simultaneously by fluorescence staining at 0, 2 and 4h of incubation. Acrosome reaction (AR) was induced by Ca++ ionophore, after capacitation. The findings indicated that both ATZ and DACT adversely affect sperm, expressed by damaged sperm membranes. ATZ had a prominent effect on epididymal-tail sperm, expressed as disruption of all examined membranes, mostly at low (0.1 or 1μM) concentrations; pseudo-AR and that induced by Ca++ ionophore were both affected by exposure to 0.1μM ATZ (P<0.05 and P<0.00004, respectively). A similar pattern was documented for sperm isolated from ejaculates (P<0.002 and P<0.001, respectively). ΔYm was affected by ATZ in sperm isolated from the epididymis tail (1μM, P<0.0009), but not in that isolated from ejaculates. DACT reduced sperm viability at all examined concentrations and in all fractions. DACT at 1μM impaired ΔΨm in sperm isolated from the epididymis tail and ejaculate (P<0.005). DACT at 100μM did not induce pseudo-AR in sperm isolated from the ejaculate, but did in sperm isolated from the epididymis tail (P<0.05). Induction of AR by Ca++ ionophore was impaired in sperm isolated from ejaculate and exposed to 10 or 100μM DACT (P<0.05) and in sperm isolated from the epididymis tail and exposed to 1, 10 or 100μM DACT (P<0.0004). These findings reveal the harmful effect of exposure to ATZ and DACT, mainly at low ecologically relevant doses, on sperm viability, AR and mitochondrial function. We conclude that sperm at advanced stages of spermatogenesis, through its passage and storage in the epididymis compartments as well as in the ejaculate, is sensitive to herbicide. The results suggest that ATZ- or DACT-induced disruptions of sperm membranes might impair sperm fertilization competence.

Herbicide-resistance mutations may impose a fitness penalty in herbicide-free environments. Moreover, the fitness penalty associated with herbicide resistance is not a stable parameter and can be influenced by ecological factors. Here, we used two Brachypodium hybridum accessions collected from the same planted forest, sensitive (S) and target-site resistance (TSR) to photosystem II (PSII) inhibitors, to study the effect of agro-ecological parameters on fitness penalty. Both accessions were collected in the same habitat, thus, we can assume that the genetic variance between them is relatively low. This allow us to focus on the effect of PSII TSR on plant fitness. S plants grains were significantly larger than those of the TSR plants and this was associated with a higher rate of germination. Under low radiation, the TSR plants showed a significant fitness penalty relative to S plants. S plants exhibiting dominance when both types of plants were grown together in a low-light environment. In contrast to previous documented studies, under high-light environment our TSR accession didn’t show any significant difference in fitness compared to the S accession. Nitrogen deficiency had significant effect on the R compared to the S accession and was demonstrated in significant yield reduction. TSR plants also expressed a high fitness penalty, relative to the S plants, when grown in competition with wheat plants. Two evolutionary scenarios can be suggested to explain the coexistence of both TSR and S plants in the same habitat. The application of PSII inhibitors may have created selective pressure toward TSR dominancy; termination of herbicide application gave an ecological advantage to S plants, creating changes in the composition of the seed bank. Alternatively, the high radiation intensities found in the Mediterranean-like climate may reduce the fitness penalty associated with TSR. Our results may suggest that by integrating non-herbicidal approaches into weed-management programs, we can reduce the agricultural costs associated with herbicide resistance. © 2017 Frenkel, Matzrafi, Rubin and Peleg.

The irrigation and fertilization regime of different varieties of Grevillea in Israel are based on existing knowledge for growing various varieties of the Proteaceae family for production of cut flowering branches. However, growers face problems in cultivating Grevillea "Spiderman," such as leaf chlorosis, prolonged growth until flowering, and reduced quality of cut flowering branches. The present study aimed to examine whether these problems stem from deficiency or excess of Fe, Mn, Zn, P, and Mg, focusing on the effect of these nutrients on growth, flowering, and appearance of visual leaf symptoms and on yield, quality, and vase life longevity of cut flowering branches. The nutrient treatments significantly affected plant development and flowering. Increasing the Fe concentration from 1 to 2 or 3 mg l-1 resulted in improved leaf color, from slightly yellow to dark green. The combination of 2 mg l-1 Fe + 1.8 mg l-1 Mn resulted in early flowering, highest yield, and development of long lateral branches. Low levels of P caused in the first year of treatment leaf chlorosis, which was intensified during the third year, resulting in severe yellowing of the flowering branches. Leaf necrosis and tip burn appeared in treatments with high concentrations of Zn, Mn, and Mg. Deficiency of Fe and Mn and high concentration of P and Mg led to the development of a large number of branches without flowers. The optimal fertilization treatment that yielded the highest quality of flowering branches after harvest was 2 mg l-1 Fe. Branches of this treatment had green foliage at harvest and the longest vase life (10 days) following the recommended postharvest treatment and air transport simulation. Based on the findings of the present research, it can be concluded that the problems in the cultivation of G. "Spiderman," such as leaf chlorosis, delayed flowering, and reduced quality of flowering branches, result from improper fertilization. © 2017 by Koninklijke Brill NV, Leiden, The Netherlands.

Humans are highly social beings that interact with each other on a daily basis. In these complex interactions, we get along by being able to identify others’ actions and infer their intentions, thoughts and feelings. One of the major theories accounting for this critical ability assumes that the understanding of social signals is based on a primordial tendency to simulate observed actions by activating a mirror neuron system. If mirror neuron regions are important for action and emotion recognition, damage to regions in this network should lead to deficits in these domains. In the current behavioural and EEG study, we focused on the lateral prefrontal cortex including dorsal and ventral prefrontal cortex and utilized a series of task paradigms, each measuring a different aspect of recognizing others’ actions or emotions from body cues. We examined 17 patients with lesions including (n = 8) or not including (n = 9) the inferior frontal gyrus, a core mirror neuron system region, and com