Z Boson Decay into Light and Darkness.

We study the Z→γγ[over ¯] process in which the Z boson decays into a photon γ and a massless dark photon γ[over ¯], when the latter couples to standard-model fermions via dipole moments. This is a simple yet nontrivial example of how the Landau-Yang theorem-ruling out the decay of a massive spin-1 particle into two photons-is evaded if the final particles can be distinguished. The striking signature of this process is a resonant monochromatic single photon in the Z-boson center of mass together with missing momentum. LEP experimental bounds allow a branching ratio up to about 10^{-6} for such a decay. In a simplified model of the dark sector, the dark-photon dipole moments arise from one-loop exchange of heavy dark fermions and scalar messengers. The corresponding prediction for the rare Z→γγ[over ¯] decay width can be explored with the large samples of Z bosons foreseen at future colliders.

Hunting Down Massless Dark Photons in Kaon Physics.

If dark photons are massless, they couple to standard-model particles only via higher dimensional operators, while direct (renormalizable) interactions induced by kinetic mixing, which motivates most of the current experimental searches, are absent. We consider the effect of possible flavor-changing magnetic-dipole couplings of massless dark photons in kaon physics. In particular, we study the branching ratio for the process K^{+}→π^{+}π^{0}γ[over ¯] with a simplified-model approach, assuming the chiral quark model to evaluate the hadronic matrix element. Possible effects in the K^{0}-K[over ¯]^{0} mixing are taken into account. We find that branching ratios up to O(10^{-7}) are allowed-depending on the dark-sector masses and couplings. Such large branching ratios for K^{+}→π^{+}π^{0}γ[over ¯] could be of interest for experiments dedicated to rare K^{+} decays like NA62 at CERN, where γ[over ¯] can be detected as a massless invisible system.

Plant growth promoting rhizobacteria (PGPR) application for coping with salinity and drought: a bibliometric network multi-analysis.

Rhizobacteria play a crucial role in plant growth and yield, stimulating primary production and improving stress resistance. Climate change has several consequences worldwide that affect arable land and agriculture. Studies on plant-soil-microorganism interactions to enhance plant productivity and/or resistance to abiotic stress may open new perspectives. This strategy aims to make agricultural-relevant plant species able to complete their biological cycle in extreme soils with the help of inoculated or primed plant growth-promoting rhizobacteria (PGPR). We provide an overview of the evolution of interest in PGPR research in the last 30 years through: (i) a quantitative search on the Scopus database; (ii) keyword frequencies and clustering analysis, and (iii) a keyword network and time-gradient analysis. The review of scientific literature on PGPR highlighted an increase in publications in the last 15 years, and a specific time gradient on subtopics, such as abiotic stresses. The rise in PGPR as a keyword co-occurring with salinity and drought stresses aligns with the growing number of papers from countries directly or partly affected by climate change. The study of PGPR, its features, and related applications will be a key challenge in the next decades, considering climate change effects on agriculture. The increased interest in PGPR leads to deeper knowledge focused specifically on researching agriculturally sustainable solutions for soils affected by salinity and drought.

Changes in salivary flow rate and pH in pregnancy.

OBJECTIVE: To evaluate changes in pH and Flow Rate (FR) of the Unstimulated Whole Saliva (UWS) in a sample of pregnant women in different gestational periods. PATIENTS AND METHODS: After collecting demographic data and medical histories, as well as conducting an oral examination, a sample of pregnant women were instructed on how to prepare prior to the sample collection. At a time between 11.00 and 12.00 a.m., they were subjected to salivary collection (spitting method, time 5 minutes); the measurement of FR was carried out using a professionally calibrated precision scale and the pH with a portable pH meter. RESULTS: The average FR of the women's detected sample (0.40 ± 0.20 ml/min) was lower than that of non-pregnant women (0.48 ± 0.15 ml/min) of the same age (p <0.05). We observed an increase (p <0.001) of FR in the first trimester (0.56 ± 0.20 ml/min) compared to second (0.34 ± 0.14 ml/min) and third (0.31 ± 0.14 ml/min) trimester. The salivary pH of pregnant women was lower than the one detected in the non-pregnant women's sample (p <0.0001). CONCLUSIONS: Our study highlighted an increase in the FR in the first trimester compared to that detected in the second and third trimesters of pregnancy which viceversa was lower than the average FR in non-pregnant women. This data, combined with the decrease in salivary pH, supports the hypothesis that correlates the FR increase with the attempt to counter the decrease in pH due to gastric regurgitation frequent in the first trimester. Further studies are necessary to evaluate salivary FR and pH in pregnant women samples related to the emesis phenomenon.

Suitability of Solanum lycopersicum L. 'Microtom' for growth in Bioregenerative Life Support Systems: exploring the effect of high-LET ionising radiation on photosynthesis, leaf structure and fruit traits.

The realisation of manned space exploration requires the development of Bioregenerative Life Support Systems (BLSS). In such self-sufficient closed habitats, higher plants have a fundamental role in air regeneration, water recovery, food production and waste recycling. In the space environment, ionising radiation represents one of the main constraints to plant growth. In this study, we explore whether low doses of heavy ions, namely Ca 25 Gy, delivered at the seed stage, may induce positive outcomes on growth and functional traits in plants of Solanum lycopersicum L. 'Microtom'. After irradiation of seed, plant growth was monitored during the whole plant life cycle, from germination to fruit ripening. Morphological parameters, photosynthetic efficiency, leaf anatomical functional traits and antioxidant production in leaves and fruits were analysed. Our data demonstrate that irradiation of seeds with 25 Gy Ca ions does not prevent achievement of the seed-to-seed cycle in 'Microtom', and induces a more compact plant size compared to the control. Plants germinated from irradiated seeds show better photochemical efficiency than controls, likely due to the higher amount of D1 protein and photosynthetic pigment content. Leaves of these plants also had smaller cells with a lower number of chloroplasts. The dose of 25 Gy Ca ions is also responsible for positive outcomes in fruits: although developing a lower number of berries, plants germinated from irradiated seeds produce larger berries, richer in carotenoids, ascorbic acid and anthocyanins than controls. These specific traits may be useful for 'Microtom' cultivation in BLSS in space, in so far as the crew members could benefit from fresh food richer in functional compounds that can be directly produced on board.

RheoDSC: a hyphenated technique for the simultaneous measurement of calorimetric and rheological evolutions.

A newly developed hyphenated technique is presented combining an existing rheometer and differential scanning calorimeter into a single experimental setup. Through the development of a fixation accessory for differential scanning calorimeter (DSC) crucibles and a novel rotor, the simultaneous measurement is performed inside the well-controlled thermal environment of a Tzero DSC cell. Hence, the evolution of thermal and flow properties of a material can be simultaneously measured using steady or oscillatory shear measurements and regular or modulated temperature DSC measurements. Along with the construction of a prototype, a validation of the design was performed. The technique offers interesting opportunities for the investigation of flow-induced transitions, for instance, crystallization or phase separation, and provides an asset for high-throughput screening of materials. The potential of the novel technique is demonstrated by two case studies: the chemorheology during the cure of a thermosetting epoxy-amine system and the flow-induced crystallization of syndiotactic polypropylene.

[Management of anticoagulants in ophthalmic surgery-a survey among ophthalmic surgeons in Germany]. / Umgang mit gerinnungshemmenden Substanzen in der Ophthalmochirurgie ­ eine Umfrage unter Ophthalmochirurgen in Deutschland.

INTRODUCTION: As our population ages and comorbidities rise, ophthalmic surgeons are increasingly faced with patients on anticoagulant therapy or with clotting disorders. The ophthalmic surgeon has to weigh the perioperative risk of haemorrhage when anticoagulation continues against the risk of thromboembolism caused by discontinuation or changing the patient's medication (bridging, switching, cessation). There are currently no guidelines or recommendations. METHODS: A survey was sent to the DOG (German Ophthalmologic Society) divisions and associated surgical organizations to determine the status quo. A questionnaire was sent out and filled out by the different groups of specialists. RESULTS: All four divisions of the DOG and four associated organizations returned completed questionnaires. Surgical interventions were listed that are carried out during anticoagulant therapy without exceptions, as well as interventions that were classified to require medical adjustment. Although the assessments varied, general consensus was achieved regarding interventions not requiring adjustments due to anticoagulants (i. e., intravitreal injection, cataract surgery, laser and corneal operations, simple muscle surgery), and those interventions requiring adjustments in medications (glaucoma operations, complex retina surgery, eye socket surgery, complex surgery of the lid). CONCLUSION: Main result of this survey was the specification of serious bleeding complications which are permanent vision loss and re-operation. They could serve as endpoint parameters for essential future investigations. Nevertheless, this survey makes clear that the decision about an adjustment of anticoagulant medication in ophthalmic surgery is currently made individually and not based on established standards.

The use of modulated temperature differential scanning calorimetry for the characterisation of food systems.

Modulated temperature Differential Scanning Calorimetry (MTDSC) is used to characterise food systems. It is shown that by splitting the total heat flow into reversing (related to heat capacity) and non-reversing contributions, overlapping thermal events can be separated. The combination of excellent sensitivity and high resolution provides more accurate results for weak and/or broad transitions. The thermal transitions of maltotriose, maltohexaose and thermoplastic starch are treated as examples. It is also shown that MTDSC is very useful to follow in situ slow crystallisation processes. These structural changes are detected by measuring the heat capacity in the quasi-isothermal mode. The (quasi-)isothermal crystallisation of pregelatinized waxy corn starch is given as an example.

A 46,XX,10Q+ chromosome constitution in a girl. Partial long arm duplication or insertional translocation?

A girl with slight psychomotor retardation, microphthalmia, and colobomata of the left eye, a hypotrophy of the right arm and a surnumerary digit on the right hand is described. The routine chromosome analysis and a G-banding analysis revealed an elongated long arm of chromosome 10. An extra light and dark band was present proximally. Both parents had normal chromosomes. While the visual comparison of the abnormal with the normal chromosome 10, did not enable the extra bands of the normal bands q21 and q22 to be distinguished. However, measurements of length, surface area, and relative reflection of the different light and dark bands of the long arm on tracings or directly on the normal and abnormal chromosomes, enabled us to precisely locate the extra bands and to determine that the abnormal chromosome was a result of an insertional translocation. The value of such measurements is discussed.

Complete trisomy 5p owing to de novo translocation t(5;22)(q11;p11) with isochromosome 5p associated with a familial pericentric inversion of chromosome 2, inv 2(p21q11).

A boy with a de novo translocation (5;22) and isochromosome 5p associated with a pericentric inversion of chromosome 2 (p21q11) is described. The pericentric inversion was also present in the mother. The main clinical features of the 'complete trisomy 5p' syndrome were present in the proband.

Trisomy 10p, due to an unusual translocation.

A mentally retarded boy with short stature, craniofacial dysmorphia, clubfeet, hypertonia and several other congenital anomalies is described. Chromosome analysis revealed a trisomy 10p, due to a peculiar t(10 ; 14) (p11 ; p12) translocation.

Extra Yq and partial monosomy 12p due to a Y;12 translocation in a boy with features of the 12p deletion syndrome.

A Y;12 translocation, resulting in extra Yq material and partial monosomy 12p, was found in a 7 1/2 year old boy. He showed growth and mental retardation and several of the congenital anomalies seen in the 12p deletion syndrome. LDHB activity, the gene for which is located at 12p12, was normal in serum, in accordance with the suspected 12p13 deletion in the patient.