Disruption of Ripple-Associated Hippocampal Activity During Rest Impairs Spatial Learning in the Rat

The hippocampus plays a key role in the acquisition of new memories for places and events. Evidence suggests that the consolidation of these memories is enhanced during sleep. At the neuronal level, reactivation of awake experience in the hippocampus during sharp-wave ripple events, characteristic of slow-wave sleep, has been proposed as a neural mechanism for sleep-dependent memory consolidation. However, a causal relation between sleep reactivation and memory consolidation has not been established. Here we show that disrupting neuronal activity during ripple events impairs spatial learning. We trained rats daily in two identical spatial navigation tasks followed each by a 1-hour rest period. After one of the tasks, stimulation of hippocampal afferents selectively disrupted neuronal activity associated with ripple events without changing the sleep-wake structure. Rats learned the control task significantly faster than the task followed by rest stimulation, indicating that interfering with hippocampal processing during sleep led to decreased learning.Institute of Physical and Chemical Research (Japan)National Institutes of Health (U.S.)Human Frontier Science Program (Grant Number: RO1 MH061976

Secondary Instabilities of Surface Waves on Viscous Fluids in the Faraday Instability

Secondary instabilities of Faraday waves show three regimes: (1) As seen previously, low-viscosity (nu) fluids destabilize first into squares. At higher driving accelerations a, squares show low-frequency modulations corresponding to the motion of phase defects, while theory predicts a stationary transverse amplitude modulation (TAM). (2) High-nu fluids destabilize first to stripes. Stripes then show an oscillatory TAM whose frequency is incommensurate with the driving frequency. At higher a, the TAM undergoes a phase instability. At still higher a, edge dislocations form and fluid droplets are ejected. (3) Intermediate-nu fluids show a complex coexistence of squares and stripes, as well as stationary and oscillatory TAM instabilities of the stripes.Comment: REVTEX, with 3 separate uuencoded figures, to appear in Europhys. Let

Involvement of Maasai Pastoralists in Participatory Rangeland Management Planning and Implementation

The pastoral Maasai lifestyle was and still is traditionally based on subsistence dairy and meat production. But with population increase, the rangelands can no longer sustainably support livestock production systems. Most of the rangelands which are used for grazing have been subdivided and partially cleared to pave way for cultivation, because of increased population pressure (Ego et al., 1999). This has led to a tendency to overgraze, thus impacting negatively on secondary production from the range. In order to effectively reverse this trend, the users of the rangeland resources were brought together to analyse constraints and opportunities for sustainable use, so that they could develop action plans for the improvement of the rangelands

Ethnopharmacology, Antimicrobial Potency, and Phytochemistry of African Combretum and Pteleopsis Species (Combretaceae): A Review

Bacterial and fungal resistance to antibiotics is of growing global concern. Plants such as the African Combretum and Pteleopsis species, which are used in traditional medicine for the treatment of infections, could be good sources for antimicrobial extracts, drug scaffolds, and/or antibiotic adjuvants. In African countries, plant species are often used in combinations as traditional remedies. It is suggested that the plant species enhance the effects of each other in these combination treatments. Thus, the multi-species-containing herbal medications could have a good antimicrobial potency. In addition, plant extracts and compounds are known to potentiate the effects of antibiotics. The objective of this review is to compile the information on the botany, ethnopharmacology, ethnobotany, and appearance in herbal markets of African species of the genera Combretum and Pteleopsis. With this ethnobotanical information as a background, this review summarizes the information on the phytochemistry and antimicrobial potency of the extracts and their active compounds, as well as their combination effects with conventional antibiotics. The databases used for the literature search were Scopus, Elsevier, EBSCOhost, PubMed, Google Scholar, and SciFinder. In summary, a number of Combretum and Pteleopsis species were reported to display significant in vitro antibacterial and antifungal efficacy. Tannins, terpenes, flavonoids, stilbenes, and alkaloids—some of them with good antimicrobial potential—are known from species of the genera Combretum and Pteleopsis. Among the most potent antimicrobial compounds are arjunglucoside I (MIC 1.9 µg/mL) and imberbic acid (MIC 1.56 µg/mL), found in both genera and in some Combretum species, respectively. The in vitro antimicrobial properties of the extracts and compounds of many Combretum and Pteleopsis species support their traditional medicinal uses

Dry flower disease of Macadamia in Australia caused by Neopestalotiopsis macadamiae sp. nov. and Pestalotiopsis macadamiae sp. nov

Incidence of dry flower disease of macadamia (Macadamia integrifolia), expressed as blight of the flowers, necrosis and dieback of the rachis, is increasing in Australia. In the 2012/13 production season, incidence of dry flower disease resulted in 10% to 30% yield loss in the affected orchards. Etiology of the disease has not been established. This study was established to characterise the disease and identify the causal pathogen. A survey of the major macadamia producing regions in Australia revealed dry flower disease symptoms, regardless of cultivar or location at all stages of raceme development. Based on colony and conidial morphology, the majority (41%) of fungal isolates obtained from tissue samples were identified as Pestalotiopsis and Neopestalotiopsis spp. The phylogeny of the combined partial sequence of the internal transcribed spacer, beta-tubulin and translation elongation factor 1-alpha gene loci, segregated the isolates into two well supported clades, independent of location or part of the inflorescence affected. Further morphological examination supported the establishment of two new species, which are formally described as Neopestalotiopsis macadamiae sp. nov. and Pestalotiopsis macadamiae sp. nov. Using spore suspensions of isolates of both species, Koch?s postulates were fulfilled on three macadamia cultivars at all stages of raceme development. To our knowledge, this is the first report of species of Neopestalotiopsis and Pestalotiopsis as causal agents of inflorescence disease in macadamia

Effect of Oral Alendronate on Bone Mineral Density and the Incidence of Fractures in Postmenopausal Osteoporosis

BACKGROUND Postmenopausal osteoporosis is a serious health problem, and additional treatments are needed. METHODS We studied the effects of oral alendronate, an aminobisphosphonate, on bone mineral density and the incidence of fractures and height loss in 994 women with postmenopausal osteoporosis. The women were treated with placebo or alendronate (5 or 10 mg daily for three years, or 20 mg for two years followed by 5 mg for one year); all the women received 500 mg of calcium daily. Bone mineral density was measured by dual-energy x-ray absorptiometry. The occurrence of new vertebral fractures and the progression of vertebral deformities were determined by an analysis of digitized radiographs, and loss of height was determined by sequential height measurements. RESULTS The women receiving alendronate had significant, progressive increases in bone mineral density at all skeletal sites, whereas those receiving placebo had decreases in bone mineral density. At three years, the mean (±SE) differences in bone mineral density between the women receiving 10 mg of alendronate daily and those receiving placebo were 8.8±0.4 percent in the spine, 5.9±0.5 percent in the femoral neck, 7.8±0.6 percent in the trochanter, and 2.5±0.3 percent in the total body (P CONCLUSIONS Daily treatment with alendronate progressively increases the bone mass in the spine, hip, and total body and reduces the incidence of vertebral fractures, the progression of vertebral deformities, and height loss in postmenopausal women with osteoporosis

Knowledge and acceptance of COVID-19 vaccine among healthcare workers in Enugu metropolis, Enugu state, Nigeria

BackgroundCOVID-19 disease spread at an alarming rate, and was declared a pandemic within 5 months from the first reported case. As vaccines have become available, there was a global effort to attain about 75% herd immunity through vaccination. There is a need to address the issue of vaccine hesitancy to COVID-19 vaccines especially in places such as Sub-Saharan African countries which have a high rate of background vaccine hesitancy.ObjectiveTo determine the knowledge and acceptance of COVID-19 vaccines among healthcare workers (HCWs) in Enugu metropolis.MethodsA cross-sectional descriptive study of 103 HCWs in Enugu metropolis was done. Data was collected using structured online Google forms. Descriptive and inferential statistics was done using SPSS, and results were summarized into percentages and associations.ResultsAn acceptance rate of 56.2% was obtained among HCWs in Enugu metropolis. Positive predicators of acceptance include older age (p = 0.004, X2 = 13.161), marriage (p = 0.001, X2 = 13.996), and higher average level of income (p = 0.013, X2 = 10.766) as significant correlations were found. No significant association was found between educational level, religion, denomination nor occupation, and acceptance of vaccine. The major factor responsible for refusal was fear of side-effects.DiscussionThe acceptance rate of COVID-19 vaccines among HCWs is still less than optimal. This population represents the most enlightened population on health related matters, hence if acceptance rate remains merely average that in the general population is expected to be worse. There is a need to address the fear of vaccine side-effects by inculcating more open and interactive methods of information dissemination, while also addressing the misconceptions or myths surrounding COVID-19 vaccines

Reproductive Outcomes Following Ectopic Pregnancy: Register-Based Retrospective Cohort Study

Using Scottish national registry data, Sohinee Bhattacharya and colleagues investigate pregnancy outcomes following ectopic pregnancy in comparison to livebirth, miscarriage, or termination in a first pregnancy

Impact of cognitive stimulation on ripples within human epileptic and non-epileptic hippocampus

Background: Until now there has been no way of distinguishing between physiological and epileptic hippocampal ripples in intracranial recordings. In the present study we addressed this by investigating the effect of cognitive stimulation on interictal high frequency oscillations in the ripple range (80-250 Hz) within epileptic (EH) and non-epileptic hippocampus (NH). Methods: We analyzed depth EEG recordings in 10 patients with intractable epilepsy, in whom hippocampal activity was recorded initially during quiet wakefulness and subsequently during a simple cognitive task. Using automated detection of ripples based on amplitude of the power envelope, we analyzed ripple rate (RR) in the cognitive and resting period, within EH and NH. Results: Compared to quiet wakefulness we observed a significant reduction of RR during cognitive stimulation in EH, while it remained statistically marginal in NH. Further, we investigated the direct impact of cognitive stimuli on ripples (i.e. immediately post-stimulus), which showed a transient statistically significant suppression of ripples in the first second after stimuli onset in NH only. Conclusion: Our results point to a differential reactivity of ripples within EH and NH to cognitive stimulation