On long-term modulation of the Sun’s magnetic cycle

We utilize reconstructions based on cosmogenic radionuclides as well as direct observations of solar magnetic activity, to argue that the solar dynamo has operated similarly to the present day for at least the past 10 000 yr. The persistence of the 87-yr Gleissberg cycle throughout supermodulation events suggests that the Hale and Schwabe cycles continue independently of the modulational mechanism for activity. We further analyse behaviour of solar activity during the Spörer and Maunder Minima. Such grand minima recur with the characteristic de Vries period of approximately 208 yr but their incidence is modulated by the Hallstatt cycle with a characteristic period of around 2300 yr.We ascribe the latter to supermodulation, caused by breaking the symmetry of the dynamo pattern. Finally, we emphasize the need for further calculations in order to determine the effects of changes in solar field morphology and symmetry on the solar wind and on cosmic ray deflection

Patient-derived iPSCs show premature neural differentiation and neuron type-specific phenotypes relevant to neurodevelopment.

Ras/MAPK pathway signaling is a major participant in neurodevelopment, and evidence suggests that BRAF, a key Ras signal mediator, influences human behavior. We studied the role of the mutation BRAFQ257R, the most common cause of cardiofaciocutaneous syndrome (CFC), in an induced pluripotent stem cell (iPSC)-derived model of human neurodevelopment. In iPSC-derived neuronal cultures from CFC subjects, we observed decreased p-AKT and p-ERK1/2 compared to controls, as well as a depleted neural progenitor pool and rapid neuronal maturation. Pharmacological PI3K/AKT pathway manipulation recapitulated cellular phenotypes in control cells and attenuated them in CFC cells. CFC cultures displayed altered cellular subtype ratios and increased intrinsic excitability. Moreover, in CFC cells, Ras/MAPK pathway activation and morphological abnormalities exhibited cell subtype-specific differences. Our results highlight the importance of exploring specific cellular subtypes and of using iPSC models to reveal relevant human-specific neurodevelopmental events

HIV knowledge, disclosure and sexual risk among pregnant women and their partners in rural South Africa

Partner involvement has been deemed fundamental for the prevention of mother-to-child transmission (PMTCT) of HIV, although it remains difficult to achieve. This study aimed to explore the attitudes and behaviours of pregnant women and their partners who participated in a behavioural risk reduction intervention in six community health centres in the Mpumalanga province of South Africa. Qualitative methods only were used in this study. Women and their partners took part in four gender-concordant groups that addressed HIV, PMTCT, disclosure of HIV status and safer sex practices. The results indicate that men value and understand the importance of being involved in women’s reproductive health, although some components of the PMTCT programme such as condom use were still met with some resistance. Participants demonstrated high levels of HIV- and sexually transmitted infection-related knowledge. Men lacked knowledge about PMTCT but were interested in acquiring information so that they could support their partners. All groups highlighted the emotional and physical benefits of disclosing one’s HIV status. The involvement of men in antenatal care has the potential to prevent women from becoming infected with HIV both during pregnancy and post-partum when they are more vulnerable to infection and have a high risk of transmission to the infant. There is a need for interventions that focus on both increasing male involvement and promoting condom use during pregnancy.Keywords: HIV, PMTCT, disclosure, partners, risk reduction intervention, Mpumalang

Super-modulation of the Sun’s magnetic activity: the effects of symmetry changes

In this paper we argue that the solar activity record, as revealed by telescopic observations and proxy data from the abundances of cosmogenic isotopes, is consistent with the action of a deterministic nonlinear chaotic dynamo. In particular we claim that the long timescale ‘super-modulation’ apparent in the isotopic record can be ascribed to switching of the dynamo between two different modulational patterns. The first (which is currently in operation) involves deep grand minima and occasional changes in symmetry triggered by these minima. The second, which exhibits only weak modulation and no grand minima, arises as a consequence of symmetry breaking. These processes are demonstrated for highly idealized simple models of the nonlinear dynamo equations

Efficacy of a lay health worker led group antiretroviral medication adherence training among non-adherent HIV-positive patients in KwaZulu-Natal, South Africa: Results from a randomized trial

There is a lack of theory-based randomized controlled trials to examine the effect of antiretroviral adherence in sub-Saharan Africa. We assessed the effectiveness of a lay health worker lead structured group intervention to improve adherence to antiretroviral therapy (ART) in a cohort of HIV-infected adults. This two-arm randomized controlled trial was undertaken at an HIV clinic in a district hospital in South Africa. A total of 152 adult patients on ART and with adherence problems were randomized 1:1 to one of two conditions, a standard adherence intervention package plus a structured three session group intervention or to a standard adherence intervention package alone. Self-reported adherence was measured using the Adult AIDS Clinical Trials Group adherence instrument prior to, post intervention and at follow-up. Baseline characteristics were similar for both conditions. At post-intervention, adherence information knowledge increased significantly in the intervention condition in comparison to the standard of care, while adherence motivation and skills did not significantly change among the conditions over time. There was a significant improvement in ART adherence and CD4 count and a significant reduction of depression scores over time in both conditions, however, no significant intervention effect between conditions was found. Lay healthworkers may be a useful adjunct to treatment to enhance the adherence information component of the medication adherence intervention, but knowledge may be necessary but not sufficient to increase adherence in this sample. Psychosocial informational interventions may require more advanced skill training in lay health workers to achieve superior adherenceoutcomes in comparison standard care in this resource-constrained setting

Temperature effects on zoeal morphometric traits and intraspecific variability in the hairy crab Cancer setosus across latitude

International audiencePhenotypic plasticity is an important but often ignored ability that enables organisms, within species-specific physiological limits, to respond to gradual or sudden extrinsic changes in their environment. In the marine realm, the early ontogeny of decapod crustaceans is among the best known examples to demonstrate a temperature-dependent phenotypic response. Here, we present morphometric results of larvae of the hairy crab , the embryonic development of which took place at different temperatures at two different sites (Antofagasta, 23°45′ S; Puerto Montt, 41°44′ S) along the Chilean Coast. Zoea I larvae from Puerto Montt were significantly larger than those from Antofagasta, when considering embryonic development at the same temperature. Larvae from Puerto Montt reared at 12 and 16°C did not differ morphometrically, but sizes of larvae from Antofagasta kept at 16 and 20°C did, being larger at the colder temperature. Zoea II larvae reared in Antofagasta at three temperatures (16, 20, and 24°C) showed the same pattern, with larger larvae at colder temperatures. Furthermore, larvae reared at 24°C, showed deformations, suggesting that 24°C, which coincides with temperatures found during strong EL Niño events, is indicative of the upper larval thermal tolerance limit.   is exposed to a wide temperature range across its distribution range of about 40° of latitude. Phenotypic plasticity in larval offspring does furthermore enable this species to locally respond to the inter-decadal warming induced by El Niño. Morphological plasticity in this species does support previously reported energetic trade-offs with temperature throughout early ontogeny of this species, indicating that plasticity may be a key to a species' success to occupy a wide distribution range and/or to thrive under highly variable habitat conditions

Downward pumping of magnetic flux as the cause of filamentary structures in sunspot penumbrae

The structure of a sunspot is determined by the local interaction between magnetic fields and convection near the Sun's surface. The dark central umbra is surrounded by a filamentary penumbra, whose complicated fine structure has only recently been revealed by high-resolution observations. The penumbral magnetic field has an intricate and unexpected interlocking-comb structure and some field lines, with associated outflows of gas, dive back down below the solar surface at the outer edge of the spot. These field lines might be expected to float quickly back to the surface because of magnetic buoyancy, but they remain submerged. Here we show that the field lines are kept submerged outside the spot by turbulent, compressible convection, which is dominated by strong, coherent, descending plumes. Moreover, this downward pumping of magnetic flux explains the origin of the interlocking-comb structure of the penumbral magnetic field, and the behaviour of other magnetic features near the sunspot

Sexual risk reduction among Zambian couples

Zambia has over 1 million HIV infections nationwide and an urban prevalence rate of 23%. This study compared the impact of maleinvolvement in multiple and single session risk reduction interventions among inconsistent condom users in Zambia and the role ofserostatus among HIV-seropositive and serodiscordant couples. Couples (N=392) were randomised into intervention arms. Amonginconsistent condom users at baseline (N=83), condom use increased in both conditions and this increase was maintained over a 12-month period. At 12 months, seronegative men in the multiple session condition increased sexual barrier (male and female condoms)use in comparison with those in the single session condition (F=16.13, p=0.001) while seropositive individuals increased sexualbarrier use regardless of condition. Results illustrate the importance of both single and multiple session risk reduction counsellingamong seronegative men in serodiscordant couples in Zambia, and highlight the differing perception of risk between seropositiveand serodiscordant persons.Keywords: HIV, men, women, Africa, high-risk behaviour, behavioural intervention

Lp Fourier multipliers on compact Lie groups

In this paper we prove Lp multiplier theorems for invariant and non-invariant operators on compact Lie groups in the spirit of the well-known Hormander-Mikhlin theorem on Rn and its variants on tori Tn. We also give applications to a-priori estimates for non-hypoelliptic operators. Already in the case of tori we get an interesting refinement of the classical multiplier theorem.Comment: 22 pages; minor correction