A planar cloverleaf antenna for circularly polarized microwave fields in atomic and molecular physics experiments.

We report on the design and characterization of a compact microwave antenna for atomic and molecular physics experiments. The antenna is comprised of four loop antennas arranged in a cloverleaf shape, allowing for precise adjustment of polarization by tuning the relative phase of the loops. We optimize the antenna for left-circularly polarized microwaves at 3.5 GHz and characterize its near-field performance using ultracold NaCs molecules as a precise quantum sensor. Observing an unusually high Rabi frequency of 2π × 46.1(2) MHz, we extract an electric field amplitude of 33(2) V/cm at 22 mm distance from the antenna. The polarization ellipticity is 2.3(4)°, corresponding to a 24 dB suppression of right-circular polarization. The cloverleaf antenna is planar and provides large optical access, making it highly suitable for quantum control of atoms and molecules and potentially other quantum systems that operate in the microwave regime.

Ultracold Gas of Dipolar NaCs Ground State Molecules.

We report on the creation of bosonic NaCs molecules in their absolute rovibrational ground state via stimulated Raman adiabatic passage. We create ultracold gases with up to 22 000 dipolar NaCs molecules at a temperature of 300(50) nK and a peak density of 1.0(4)×10^{12} cm^{-3}. We demonstrate comprehensive quantum state control by preparing the molecules in a specific electronic, vibrational, rotational, and hyperfine state. We measure the ground state ac polarizability at 1064 nm along with the two-body loss rate, which we find to be universal. Employing the tunability and strength of the permanent electric dipole moment of NaCs, we induce dipole moments of up to 2.6 D at a dc electric field of 2.1(2) kV/cm and demonstrate strong microwave coupling between the two lowest rotational states with a Rabi frequency of 2π×45 MHz. A large electric dipole moment, accessible at relatively small electric fields, makes ultracold gases of NaCs molecules well suited for the exploration of strongly interacting phases of dipolar quantum matter.

Making white spots disappear! Do minimally invasive treatments improve incisor opacities in children with molar-incisor hypomineralisation?

BACKGROUND: Children with molar-incisor hypomineralisation (MIH) frequently seek aesthetic treatment for incisor opacities. Surprisingly, few studies have evaluated the clinical success of such interventions. AIM: To quantify the effectiveness of minimally invasive treatments in reducing enamel opacity visibility in children with MIH. DESIGN: This in vitro study used digital clinical images of 23 children aged 8-16 years with MIH who underwent microabrasion and/or resin infiltration for the management of incisor opacities. Standard images were taken pre-treatment and 6 months post-treatment. Image software (Image-Pro Plus® V7) was employed to convert 24-bit RGB images to 16-bit greyscale and 145× magnification. Measurement repeatability was assessed using intra-class correlation coefficients (ICCs). Post-treatment changes in visible opacity area (mm2 ) and brightness (greyscale value) were tested using the Wilcoxon signed-rank test for related samples. RESULTS: The mean total opacity surface area significantly reduced from 14.3 mm2 (SD = 7.5) to 9.4 mm2 (SD = 9.0) post-treatment. The proportion of tooth surface affected by the opacity also significantly reduced from 22.5% (SD = 10.5) to 14.7% (SD = 12.7). The mean maximum opacity brightness significantly reduced from 53 066 greyscale value (SD = 4740) to 49 040 (SD = 3796). ICC was good/excellent (0.75-1.0). CONCLUSION: Minimally invasive treatment is effective in reducing the size and brightness of discrete incisor opacities. Future research should compare objective findings with patient-reported outcomes.

Sexually dimorphic perineuronal nets in the rodent and primate reproductive circuit.

Perineuronal nets are extracellular glycoprotein structures that have been found on some neurons in the central nervous system and that have been shown to regulate their structural plasticity. Until now work on perineuronal nets has been focused on their role in cortical structures where they are selectively expressed on parvalbumin-positive neurons and are reported to restrict the experience-dependent plasticity of inhibitory afferents. Here, we examined the expression of perineuronal nets subcortically, showing that they are expressed in several discrete structures, including nuclei that comprise the brain network controlling reproductive behaviors (e.g., mounting, lordosis, aggression, and social defense). In particular, perineuronal nets were found in the posterior dorsal division of the medial amygdala, the medial preoptic nucleus, the posterior medial bed nucleus of the stria terminalis, the ventrolateral ventromedial hypothalamus and adjacent tuberal nucleus, and the ventral premammillary nucleus in both the mouse and primate brain. Comparison of perineuronal nets in male and female mice revealed a significant sexually dimorphic expression, with expression found prominently on estrogen receptor expressing neurons in the medial amygdala. These findings suggest that perineuronal nets may be involved in regulating neural plasticity in the mammalian reproductive system.

Preservation of vision by the pulvinar following early-life primary visual cortex lesions.

BACKGROUND: Conscious vision is believed to depend upon an intact primary visual cortex (V1), although injury in early life is often accompanied by the preservation of visual capacity, unlike in adulthood. The middle temporal area (MT) receives input from the retinorecipient koniocellular layers of the lateral geniculate nucleus (LGN) and the more recently described medial subdivision of the inferior pulvinar (PIm) of the thalamus, pathways that potentially contribute to preservation of vision after early damage to V1. RESULTS: We examined the potential of these pathways to the long-term preservation of vision after permanent lesions of primate V1 in early and adult life by using a combination of neural tracing and diffusion MRI. We show that early-life V1 lesions lead to less pruning of the retina-pulvinar-MT pathway than is observed in control or adult lesion animals. CONCLUSIONS: These findings suggest that sustained visual input through the pulvinar to MT following a lesion of V1 in early life has the capacity to afford improved visual outcomes.

Trajectories and predictors of developmental skills in healthy twins up to 24 months of age.

BACKGROUND: Low birth weight and low 5-min Apgar scores have been associated with developmental delay, while older maternal age is a protective factor. Little is known about trajectories and predictors of developmental skills in infant twins, who are generally born with lower birth weights, lower Apgar scores and to older mothers. METHODS: Developmental skills were assessed at 3, 6, 9, 12, 18 and 24 months using the Ages and Stages Questionnaires in 152 twins from the Birmingham Registry for Twin and Heritability Studies. Multilevel spline and linear regression models (adjusted for gestational age, gender, maternal age) were used to estimate developmental trajectories and the associations between birth weight, maternal age and Apgar scores on developmental skills. RESULTS: Twins performed worse than singletons on communication, gross motor, fine motor, problem solving and personal-social skills (p < 0.001). Twins caught up around 6 months (score within -1 standard deviation of norm), except on gross motor skills, which did not catch up until after the age of 12 months. A one-year increase in maternal age was significantly associated with decreases in gross motor and personal-social z-scores of up to -0.09, whereas one unit increases in Apgar score increased z-scores up to 0.90 (p < 0.01). CONCLUSIONS: Healthy twins should be considered at a higher risk for developmental delay. Whether these results are comparable to preterm singletons, or whether there are twin-specific issues involved, should be further investigated in a study that uses a matched singleton control group.

The early maturation of visual cortical area MT is dependent on input from the retinorecipient medial portion of the inferior pulvinar.

The hierarchical development of the primate visual cortex and associated streams remains somewhat of a mystery. While anatomical, physiological, and psychological studies have demonstrated the early maturation of the dorsal "where"/"how" or motion cortical stream, little is known about the circuitry responsible. The influence of the retinogeniculostriate pathway has been investigated, but little attention has been paid to the role of two more recently described disynaptic retinothalamic projections to the middle temporal (MT) area, an early maturing dorsal stream cortical field, and which bypass the primary visual cortex (V1). These pathways are via the koniocellular layers of the lateral geniculate nucleus (LGN) and the medial portion of the inferior pulvinar (PIm). Both have been demonstrated in the adult nonhuman primate, but their influence during the maturation of the visual cortex is unknown. We used a combination of neural tracing and immunohistochemistry to follow the development of LGN and PIm inputs to area MT in the marmoset monkey. Our results revealed that the early maturation of area MT is likely due to the disynaptic retinopulvinar input and not the retinogeniculate input or the direct projection from V1. Furthermore, from soon after birth to adulthood, there was a dynamic shift in the ratio of input from these three structures to area MT, with an increasing dominance of the direct V1 afference.

Heritability of body mass index in pre-adolescence, young adulthood and late adulthood.

Increased body mass index (BMI) is a worldwide health issue. Individual differences in the susceptibility to increased BMI could be related to genes or environment. We performed a systematic review of genetic studies on BMI in pre-adolescence, young adulthood and late adulthood. We searched PubMed and EMBASE with heritability, body mass index, BMI, weight, height, anthropometry and twins as search terms. Studies reporting intra-pair correlations of healthy twin pairs that were raised together were included. This resulted in the inclusion of 8,179 monozygotic (MZ) and 9,977 dizygotic (DZ) twin pairs from twelve published studies in addition to individual participant data for 629 MZ and 594 DZ pairs from four twin registries. Structural equation modelling with intra-pair twin correlations showed that the heritability of BMI remained high over all age categories ranging from 61% (95% CI 54-64%) to 80% (95% CI 76-81%) for male and female subjects combined, while unique environmental influences increased from 14% (95% CI 13-15%) to 40% (95% CI 37-43%) with increasing age. Heritability of BMI remains consistently high over different age categories. Environmental changes over time do not seem to have as big a relative impact on an individual's weight as previously reported, suggesting a mainly genetic influence on variation in BMI over the years.

Retinal afferents synapse with relay cells targeting the middle temporal area in the pulvinar and lateral geniculate nuclei.

Considerable debate continues regarding thalamic inputs to the middle temporal area (MT) of the visual cortex that bypass the primary visual cortex (V1) and the role they might have in the residual visual capability following a lesion of V1. Two specific retinothalamic projections to area MT have been speculated to relay through the medial portion of the inferior pulvinar nucleus (PIm) and the koniocellular layers of the dorsal lateral geniculate nucleus (LGN). Although a number of studies have demonstrated retinal inputs to regions of the thalamus where relays to area MT have been observed, the relationship between the retinal terminals and area MT relay cells has not been established. Here we examined direct retino-recipient regions of the marmoset monkey (Callithrix jacchus) pulvinar nucleus and the LGN following binocular injections of anterograde tracer, as well as area MT relay cells in these nuclei by injection of retrograde tracer into area MT. Retinal afferents were shown to synapse with area MT relay cells as demonstrated by colocalization with the presynaptic vesicle membrane protein synaptophysin. We also established the presence of direct synapes of retinal afferents on area MT relay cells within the PIm, as well as the koniocellular K1 and K3 layers of the LGN, thereby corroborating the existence of two disynaptic pathways from the retina to area MT that bypass V1.

Chemoarchitecture of the middle temporal visual area in the marmoset monkey (Callithrix jacchus): laminar distribution of calcium-binding proteins (calbindin, parvalbumin) and nonphosphorylated neurofilament.

We studied the distributions of interneurons containing the calcium-binding proteins parvalbumin and calbindin D-28k, as well as that of pyramidal neurons containing nonphosphorylated neurofilament (NNF), in the middle temporal visual area (MT) of marmoset monkeys. The distributions of these classes of cells in MT are distinct from those found in adjacent areas. Similar to the primary visual area (V1), in MT, calbindin-immunopositive neurons can be objectively classified into "dark" and "light" subtypes based on optical density of stained cell bodies. Calbindin-positive dark neurons are particularly concentrated in layers 2 and 3, whereas light neurons have a more widespread distribution. In addition, a subcategory of calbindin-positive dark neuron, characterized by a "halo" of stained processes surrounding the cell body, is found within and around layer 4 of MT and V1. These cells are rare in most other visual areas. In comparison, parvalbumin-immunopositive cells in area MT have a relatively homogeneous distribution, although with a trend toward higher spatial density in lower layer 3, and are relatively uniform in terms of density of staining. Finally, MT shows a characteristic trilaminar distribution of NNF-immunopositive pyramidal cells, with stained cell bodies evident in layers 3, 5, and 6. Although the laminar distribution of cells stained for the three markers overlap to some extent, these subcategories can be readily distinguished in terms of morphology, including cell body size. Chemoarchitectural parallels observed between MT and V1 suggest comparable physiological requirements and neuronal circuitry.

Topographic and laminar maturation of striate cortex in early postnatal marmoset monkeys, as revealed by neurofilament immunohistochemistry.

The maturation of pyramidal neurons in the primary visual cortex (V1) of marmoset monkeys was investigated using an antibody (SMI-32) to non-phosphorylated neurofilament protein (NNF). Analysis of animals aged between birth and postnatal day 91 (PD 91, which corresponds approximately to the peak of synaptogenesis in this species) revealed discrete changes in both the laminar and the areal distribution of NNF. At PD 0, the upper part of layer 6 contained darkly labelled neurons and associated neuropil, including axons. In this layer a centroperipheral gradient, with more labelled cells in the foveal representation, was apparent at PD 0. This topographic gradient gradually disappeared, and by PD 91 a similar density of labelled layer 6 cells was observed throughout V1. Labelled cells were not apparent in layer 3C until PD 7, and were not distributed according to a topographic gradient. Labelled cells were first observed in layer 3B(alpha) at PD 28, when they formed a centroperipheral gradient similar to that seen in layer 6. This gradient was still evident in an adult animal. These results demonstrate an inside-out profile of postnatal cortical development, with the topographic pattern of maturation of V1 mimicking the centroperipheral gradient of maturation in the retina.

Loss of myosin VI reduces secretion and the size of the Golgi in fibroblasts from Snell's waltzer mice.

Golgi morphology and function are dependent on an intact microtubule and actin cytoskeleton. Myosin VI, an unusual actin-based motor protein moving towards the minus ends of actin filaments, has been localized to the Golgi complex at the light and electron microscopic level. Myosin VI is present in purified Golgi membranes as a peripheral membrane protein, targeted by its globular tail domain. To investigate the function of myosin VI at the Golgi complex, immortal fibroblastic cell lines of Snell's waltzer mice lacking myosin VI were established. In these cell lines, where myosin VI is absent, the Golgi complex is reduced in size by approximately 40% compared with wild-type cells. Furthermore, protein secretion of a reporter protein from Snell's waltzer cells is also reduced by 40% compared with wild-type cells. Rescue experiments showed that fully functional myosin VI was able to restore Golgi complex morphology and protein secretion in Snell's waltzer cells to the same level as that observed in wild-type cells.