Measurements of vacuum magnetic birefringence using permanent dipole magnets: the PVLAS experiment

The PVLAS collaboration is presently assembling a new apparatus (at the INFN section of Ferrara, Italy) to detect vacuum magnetic birefringence (VMB). VMB is related to the structure of the QED vacuum and is predicted by the Euler-Heisenberg-Weisskopf effective Lagrangian. It can be detected by measuring the ellipticity acquired by a linearly polarised light beam propagating through a strong magnetic field. Using the very same optical technique it is also possible to search for hypothetical low-mass particles interacting with two photons, such as axion-like (ALP) or millicharged particles (MCP). Here we report results of a scaled-down test setup and describe the new PVLAS apparatus. This latter one is in construction and is based on a high-sensitivity ellipsometer with a high-finesse Fabry-Perot cavity ($>4\times 10^5$) and two 0.8 m long 2.5 T rotating permanent dipole magnets. Measurements with the test setup have improved by a factor 2 the previous upper bound on the parameter $A_e$, which determines the strength of the nonlinear terms in the QED Lagrangian: $A_e^{\rm (PVLAS)} < 3.3 \times 10^{-21}$ T$^{-2}$ 95% c.l. Furthermore, new laboratory limits have been put on the inverse coupling constant of ALPs to two photons and confirmation of previous limits on the fractional charge of millicharged particles is given

First results from the new PVLAS apparatus: a new limit on vacuum magnetic birefringence

Several groups are carrying out experiments to observe and measure vacuum magnetic birefringence, predicted by Quantum Electrodynamics (QED). We have started running the new PVLAS apparatus installed in Ferrara, Italy, and have measured a noise floor value for the unitary field magnetic birefringence of vacuum $\Delta n_u^{\rm (vac)}= (4\pm 20) \times 10^{-23}$ T$^{-2}$ (the error represents a 1$\sigma$ deviation). This measurement is compatible with zero and hence represents a new limit on vacuum magnetic birefringence deriving from non linear electrodynamics. This result reduces to a factor 50 the gap to be overcome to measure for the first time the value of $\Delta n_u^{\rm (vac,QED)}$ predicted by QED: $\Delta n_u^{\rm (vac,QED)}= 4\times 10^{-24}$ ~T$^{-2}$. These birefringence measurements also yield improved model-independent bounds on the coupling constant of axion-like particles to two photons, for masses greater than 1 meV, along with a factor two improvement of the fractional charge limit on millicharged particles (fermions and scalars), including neutrinos

New PVLAS model independent limit for the axion coupling to γγ\gamma\gamma for axion masses above 1meV

During 2014 the PVLAS experiment has started data taking with a new apparatus installed at the INFN Section of Ferrara, Italy. The main target of the experiment is the observation of magnetic birefringence of vacuum. According to QED, the ellipticity generated by the magnetic birefringence of vacuum in the experimental apparatus is expected to be $\psi^{\rm(QED)} \approx 5\times10^{-11}$. No ellipticity signal is present so far with a noise floor $\psi^{\rm(noise)} \approx 2.5\times10^{-9}$ after 210 hours of data taking. The resulting ellipticity limit provides the best model independent upper limit on the coupling of axions to $\gamma\gamma$ for axion masses above $10^{-3}$eV

Measurement of the Cotton Mouton effect of water vapour

In this paper we report on a measurement of the Cotton Mouton effect of water vapour. Measurement performed at room temperature ($T=301$ K) with a wavelength of 1064 nm gave the value $\Delta n_u = (6.67 \pm 0.45) \cdot 10^{-15}$ for the unit magnetic birefringence (1 T magnetic field and atmospheric pressure)

Use of Annual Self-Reseeding Legumes in an Oak Forest in Central Italy

A trial has been carried out for three years in an oak coppice geometrically thinned out of Mediterranean Central Italy, about the functioning of a pastoral system made by four different resources: native pasture, subterranean clover (Trifolium brachycalycinum Katzn. et Morley) in pure stand, strips thinned out and firebreaks improved with oversown subclover, all grazed by sheep. Subclover increased the forage yield and improved the palatabilty of the pasture and the regularity of grazing; the higher biomass intake by animals reduced the quantity of dried biomass in summer and contributed to keep low either fire hazards or flame diffusion speed. Data underlined the importance of deferred grazing and of the combination of different native or improved resources on the seasonal distribution of production and animal intake

Performance evaluation of Border irrigation method for cotton field

Performance evaluation of Border irrigation method was carried out for cotton field in village Kirarkot, Sirsa (Haryana). Water application, storage and distribution efficiency were estimated using measurements of soil moisture (%), infiltration rate (cm/hr), water advance and recession time (minute) during different irrigation events. The advance time increased during the growing season due to increased infiltration rate and increased resistance to flow by the growing crops. The water application efficiency of cotton field was 100 per cent as average applied depth (8.26 cm for canal irrigation and 9.06 cm for tubewell irrigation) of irrigation was less than the average required depth (10.30 cm for canal irrigation and 10.98 cm for tubewell irrigation) throughout the field plots. The observed water storage efficiency in different cotton fields varied from 72.92 - 90.08 per cent indicating under irrigation. Water distribution efficiency of cotton fields (97.8 -99.2per cent) indicated a relatively high degree of uniformity of water application. Stratified soil profile (sandy loam: 0-30 cm and sandy clay loam: 30-120 cm) of the selected fields reduced the infiltration rate to relatively very low value after 10-15 minutes creating favourable condition for uniformity of water application under border irrigation

Affective Temperaments and Somatization Among Unipolar Depression Patients and Healthy Controls

Introduction Literature describes important comorbidity rates between somatization and mood disorders. Furthermore, there are data suggesting an association between affective temperament and somatization traits in healthy subjects. Objective In the present observational study, we investigated affective temperaments and somatization aspects in clinical and healthy samples. Aim The study focused on differences between unipolar depressive inpatients (DEP) and controls (C). Method We administered to 20 DEP and 20 C following questionnaires: Mini International Neuropsychiatric Interview (MINI), 17-item Self Rating Depression Scale (SDS), Hypomania check list 32(HCL-32), Self Rating Anxiety Scale (SAS), DCPR diagnostic criteria for psychosomatic research, Brief TEMPS-A, Modified Somatic Perception Questionnaire (MSPQ), Somatosensory Amplification Scale-SSAS. DEP and C were matched for age, sex and marital status. Result About temperaments, ANOVA showed that DEP were more cyclothymic (p Conclusion Our data suggest that DEP present an important affective temperamental dysregulation. Relative to somatization aspects, DEP show a greater vulnerability than C

Identification of predatory arthropods of the invasive Halyomorpha halys through molecular gut content analysis

Halyomorpha halys (Stål, 1855) is an invasive agricultural pest in North America and Europe. Most of the information on H. halys predators in invaded areas comes from North America. This work focused on the molecular identification of arthropod predator species capable of feeding on H. halys in northern Italy. Predatory arthropods were collected in the field in four urban parks using the tree-beating technique. A real-time PCR workflow was applied to detect H. halys DNA from the gut content of predators. Of the 190 predator individuals analysed, 46 were positive for H. halys DNA and belonged to 10 insect taxa (1 Dermaptera, 3 Coleoptera, 2 Hemiptera and 4 Orthoptera) and six arachnid taxa (2 Opiliones and 6 Araneae). The integration of gut content analysis with laboratory bioassays and field observations allows the identification of a greater number of predators and therefore a better understanding of how the invaded ecosystem is responding to the introduction of a new species, given that samples are taken from the invaded environment itself. Therefore, the gut content analysis provides essential elements for conservation biocontrol in integrated pest management programmes

The PVLAS experiment for measuring the magnetic birefringence of vacuum

We describe the principle and status of the PVLAS experiment being prepared at the Department of Physics and INFN section in Ferrara, Italy. The goal of the experiment is to measure the magnetic birefringence of vacuum. This effect is directly connected to the vacuum QED structure and can be detected by measuring the ellipticity acquired by a linearly polarized laser beam traversing a strong magnetic field. Vacuum magnetic birefringence is predicted by the Euler-Heisenberg effective Lagrangian. The experimental method is also sensitive to new physics and could place new laboratory limits to hypothetical particles coupling to two photons, such as axion like particles, or millicharged particles

The species identification problem in mirids (Hemiptera: Heteroptera) highlighted by DNA barcoding and species delimitation studies

Due to the difficulties associated with detecting and correctly identifying mirids, developing an accurate species identification approach is crucial, especially for potential harmful species. Accurate identification is often hampered by inadequate morphological key characters, invalid and/or outdated systematics, and biases in the molecular data available in public databases. This study aimed to verify whether molecular characterization (i.e. DNA barcoding) is able to identify mirid species of economic relevance and if species delimitation approaches are reliable tools for species discrimination. Cytochrome c oxydase 1 (cox1) data from public genetic databases were compared with new data obtained from mirids sampled in different Italian localities, including an old specimen from private collection, showing contrasting results. Based on the DNA barcoding approach, for the genus Orthops, all sequences were unambiguously assigned to the same species, while in Adelphocoris, Lygus and Trigonotylus there were over-descriptions and/or misidentifications of species. On the other hand, in Polymerus and Deraeocoris there was an underestimation of the taxonomic diversity. The present study highlighted an important methodological problem: DNA barcoding can be a good tool for pest identification and discrimination, but the taxonomic unreliability of public DNA databases can make this method useless or even misleading