Βacterial flora isolated from the oesophageal bulb of the olive fruit fly Dacus oleae (Gmelin)

Από την οισοφαγική κύστη τελείων του Dacus oleae απομονώθηκαν 28 στελέχη διαφόρων βακτηρίων. Από αυτά, έξι ήσαν Gram-αρνητικά και ταυτοποιήθηκαν ως Pseudomonas mendecina, Moraxella nonliquefasciens (2), Alcaligenes sp., Enterobacter cloacae (2) και 22 Gram-θετικά τα οποία ταυτοποιήθηκαν ως Kurthia sp.. Staphylococcus subgroup VI, Micrococcus roseus. Bacillus pumilus, B. licheniformis (3) και Β. subtilis (15). Τα αποτελέσματα έδειξαν ότι κανένα από τα παραπάνω βακτήρια δεν απαντάται σταθερά στην οισοφαγική κύστη, πράγμα που μας οδηγεί στην υπόθεση ότι η μικροβιακή χλωρίδα του Δάκου εξαρτάται από διάφορους περιβαλλοντικούς παράγοντες. Εκφράζεται επίσης η άποψη, ότι η παρουσία των μικροοργανισμών αυτών πέρα από κάποιο συμβιοτικό ρόλο που μπορεί να παίζει, είναι δυνατόν να χρησιμεύει και ως πρόσθετη πηγή τροφής για το έντομο.In a study of the bacterial flora occurring in the adults of the olive fruit fly, Dacus oleae (Gmelin) (Diptera: Tephritidae), oesophageal diverticulum, a total of 28 strains were obtained. Six of them were Gram – negative and identified as Pseudomonas niendocina, Morarella nonliquefasciens (2), Alcaligenes sp., Enterobacter cloacae (2) and 22 Gram-positive classified as Kurthia sp., Staphylococcus subgroup VI, Micrococcus roseus, Bacillus pumilus, B. licheniformis (3) and B. subtilis(15). None of the above bacteria are strictly fixed and constantly present in the oesophageal diverticulum, suggesting that the bacterial flora associated with D. oleae depends on environmental factors, and could be used as a nutrient source for the insect apart from its possible other symbiotic role

Crystal and magnetic structure of La1−x_{1-x}Cax_{x}MnO3_{3} compound $(0.11\leq x\leq 0.175

We studied the crystal and magnetic structure of the La$_{1-x}$Ca$_{x}$MnO$_{3}$ compound for $(0.11\leq x\leq 0.175)$ using stoichiometric samples. For $x<0.13$ the system's ground state is insulating canted antiferromagnetic. For $0.13\le x \le 0.175$ e below the Jahn Teller transition temperature ($T_{\rm JT}$) the crystal structure undergoes a monoclinic distortion. The crystal structure can be described with $P 2_1/c$ space group which permits two Mn sites. The unit cell strain parameter $s=2(a-c)/(a+c)$ increases for $T<T_{\rm JT}$, taking the maximum value at the Curie point, and then decreases. Below $T_{\rm M^/M^{//}}\approx 60$ K $s$ abruptly changes slope and finally approaches T=0 K with nearly zero slope. The change of $s$ at $T_{\rm M^/M^{//}}$ is connected to a characteristic feature in the magnetic measurements. As $x$ increases towards the ferromagnetic metallic boundary, although $s$ is reduced appreciably, the monoclinic structure is preserved. The monoclinic structure is discussed with relation to the orbital ordering, which can produce the ferromagnetic insulating ground state. We also studied samples that were prepared in air atmosphere. This category of samples shows ferromagnetic insulating behavior without following the particular variation of the $s$ parameter. The crystal structure of these samples is related to the so-called O$^{*}$ ($c>a>b/\sqrt{2}$) structure

Symmetries of Pairing Correlations in Superconductor-Ferromagnet Nanostructures

Using selection rules imposed by the Pauli principle, we classify pairing correlations according to their symmetry properties with respect to spin, momentum, and energy. We observe that inhomogeneity always leads to mixing of even- and odd-energy pairing components. We investigate the superconducting pairing correlations present near interfaces between superconductors and ferromagnets, with focus on clean systems consisting of singlet superconductors and either weak or half-metallic ferromagnets. Spin-active scattering in the interface region induces all of the possible symmetry components. In particular, the long-range equal-spin pairing correlations have odd-frequency s-wave and even-frequency p-wave components of comparable magnitudes. We also analyze the Josephson current through a half-metal. We find analytic expressions and an interesting universality in the temperature dependence of the critical current in the tunneling limit.Comment: 20 pages, 5 figures, added citations, corrected typo

Nucleation of superconductivity and vortex matter in superconductor - ferromagnet hybrids

The theoretical and experimental results concerning the thermodynamical and low-frequency transport properties of hybrid structures, consisting of spatially-separated conventional low-temperature superconductor (S) and ferromagnet (F), is reviewed. Since the superconducting and ferromagnetic parts are assumed to be electrically insulated, no proximity effect is present and thus the interaction between both subsystems is through their respective magnetic stray fields. Depending on the temperature range and the value of the external field H_{ext}, different behavior of such S/F hybrids is anticipated. Rather close to the superconducting phase transition line, when the superconducting state is only weakly developed, the magnetization of the ferromagnet is solely determined by the magnetic history of the system and it is not influenced by the field generated by the supercurrents. In contrast to that, the nonuniform magnetic field pattern, induced by the ferromagnet, strongly affect the nucleation of superconductivity leading to an exotic dependence of the critical temperature T_{c} on H_{ext}. Deeper in the superconducting state the effect of the screening currents cannot be neglected anymore. In this region of the phase diagram various aspects of the interaction between vortices and magnetic inhomogeneities are discussed. In the last section we briefly summarize the physics of S/F hybrids when the magnetization of the ferromagnet is no longer fixed but can change under the influence of the superconducting currents. As a consequence, the superconductor and ferromagnet become truly coupled and the equilibrium configuration of this "soft" S/F hybrids requires rearrangements of both, superconducting and ferromagnetic characteristics, as compared with "hard" S/F structures.Comment: Topical review, submitted to Supercond. Sci. Tech., 67 pages, 33 figures, 439 reference

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P &lt; 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P &lt; 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk