Slow magnetic dynamics and hysteresis loops of a bulk ferromagnet

Magnetic dynamics of a bulk ferromagnet, a new single crystalline compound Co7(TeO3)4Br6, was studied by ac susceptibility and the related techniques. Very large Arrhenius activation energy of 17.2 meV (201 K) and long attempt time (2x10^(-4)s) span the full spectrum of magnetic dynamics inside a convenient frequency window, offering a rare opportunity for general studies of magnetic dynamics. Within the experimental window the ac susceptibility data build almost ideally semicircular Cole-Cole plots. Comprehensive study of experimental dynamic hysteresis loops of the compound is presented and interpreted within a simple thermal-activation-assisted spin lattice relaxation model for spin reversal. Quantitative agreement between the experimental results and the model's prediction for dynamic coercive field is achieved by assuming the central physical quantity, the Debye relaxation rate, to depend on frequency, as well as on the applied field strength and sample temperature. Cross-over between minor- to major hysteresis loops is carefully analyzed. Low-frequency limitations of the model, relying on domain wall pinning effects, are experimentally detected and appropriately discussed.Comment: A paragraph on dynamical-hysteresis assymetry added, text partially revised; Accepted in Physical Review

Two component butterfly hysteresis in Ru1222 ruthenocuprate

We report detailed studies of the ac susceptibility butterfly hysteresis on the Ru1222 ruthenocuprate compounds. Two separate contributions to these hysteresis have been identified and studied. One contribution is ferromagnetic-like and is characterized by the coercive field maximum. Another contribution, represented by the so called inverted maximum, is related to the unusual inverted loops, unique feature of Ru1222 butterfly hysteresis. The different nature of the two identified magnetic contributions is proved by the different temperature dependences involved. By lowering the temperature the inverted peak gradually disappears while the coercive field slowly raises. If the maximum dc field for the hysteresis is increased, the size of the inverted part of the butterfly hysteresis monotonously grows while the position of the peak saturates. In reaching saturation exponential field dependence has been demonstrated to take place. At T = 78 K the saturation field is 42 Oe.Comment: 5 pages, 5 figure

Ground state order and spin-lattice coupling in tetrahedral spin systems Cu2Te2O5X2

High-resolution ac susceptibility and thermal conductivity measurement on Cu2Te2O5X2(X=Br,Cl) single crystals are reported. For Br-sample, sample dependence prevents to distinguish between possibilities of magnetically ordered and spin-singlet ground states. In Cl-sample a three-dimensional transition at 18.5 K is accompanied by almost isotropic behavior of susceptibility and almost switching behavior of thermal conductivity. Thermal conductivity studies suggest the presence of a tremendous spin-lattice coupling characterizing Cl- but not Br-sample. Below the transition Cl-sample is in a complex magnetic state involving AF order but also the elements consistent with the presence of a gap in the excitation spectrum.Comment: version accepted for publication in Phys.Rev.B-Rapid Communicatio

TSH-CHECK-1 test: diagnostic accuracy and potential application to initiating treatment for hypothyroidism in patients on anti-tuberculosis drugs.

Thyroid-stimulating hormone (TSH) promotes expression of thyroid hormones which are essential for metabolism, growth, and development. Second-line drugs to treat tuberculosis (TB) can cause hypothyroidism by suppressing thyroid hormone synthesis. Therefore, TSH levels are routinely measured in TB patients receiving second-line drugs, and thyroxin treatment is initiated where indicated. However, standard TSH tests are technically demanding for many low-resource settings where TB is prevalent; a simple and inexpensive test is urgently needed

Building a Web marketing experience: the Maltese case of Where's Everybody

L’attività di web marketing, concepita fino ad oggi come esclusiva dell’impresa, sta vivendo un’evoluzione in senso sociale e partecipativo che dipende dall’evoluzione stessa del Web. Quello che in particolare si modifica non è lo scopo, che rimane sempre la soddisfazione del cliente e la sua fidelizzazione, ma l’avere a disposizione di utilizzo una “cassetta degli strumenti” più ampia e malleabile. Partendo dalla considerazione di questo fatto, la scelta dell’argomento del presente lavoro di ricerca è avvenuta in seguito a un’esperienza lavorativa di tre mesi presso il Dipartimento di Marketing & Public Relation di Where’s Everybody, una delle maggiori aziende di produzione televisiva a Malta. Questa opportunità mi è stata offerta grazie a una borsa di studio del Progetto Leonardo. Alla luce di questa prospettiva, si è cercato innanzitutto di fornire un’accurata analisi delle variabili del macro-ambiente che rendono Malta un caso particolare in Europa, sia economico, politico che sociale e culturale. In seguito si è definito il micro-ambiente, ovvero il panorama televisivo locale e la concorrenza, con particolare attenzione alla descrizione e al target dei programmi di Where’s Everybody. Il capitolo successivo è dedicato a come il Web 2.0 sta modificando gli assi portanti dell’attività di marketing, e in generale al marketing 2.0. In particolare, saranno delineate le principali caratteristiche del web marketing, non tutte ma soltanto quelle relative al lavoro svolto e all’azienda presa in considerazione. Queste sono: lo spostamento di valore dalla transazione alla relazione; il paradigma di comunicazione many-to-many e i suoi elementi fondanti (comunità virtuale, user-generated content e passaparola); l’empowerment del consumatore e il cambiamento della definizione del marketing mix. Queste considerazioni vengono applicate nella seconda parte del lavoro, in cui vengono analizzati gli strumenti e le applicazioni di web marketing utilizzati dall’azienda maltese, prima, dopo e durante il mio periodo di lavoro. Essi sono analizzati per siti Internet, social networks e servizi streaming e on-demand. In particolare, l’analisi dei punti di forza e di debolezza dell’impiego di questi strumenti serve come spunto per presentare suggerimenti di miglioramento per la strategia complessiva, in accordo con i concetti chiave del Web 2.0, ovvero collaborazione e partecipazione degli utenti. Con ciò si dimostra che Where’s Everybody ha saputo cogliere le opportunità di evoluzione del marketing in un’ottica 2.0, comprovate dai dati forniti dall’Authority delle Comunicazioni e dalle indagini di mercato svolte dalla Media Warehouse di Malta. Lo scopo finale è quindi quello di fornire, in prima istanza, una mappatura generale dello scenario di cambiamento del Web 2.0 e conseguentemente dell’attività di marketing. In seconda istanza, preso il caso pratico di una casa di produzione televisiva non italiana, il presente lavoro si propone di offrire un esempio di azienda capace di sfruttare al meglio le effettive potenzialità dei nuovi strumenti di web marketing, sottolineando le strategie adottate e l’abilità di creare valore aggiunto per i suoi clienti

Integrated care as a means to improve primary care delivery for adults and adolescents in the developing world: a critical analysis of Integrated Management of Adolescent and Adult Illness (IMAI)

Background: More than three decades after the 1978 Declaration of Alma-Ata enshrined the goal of ‘health for all’, high-quality primary care services remain undelivered to the great majority of the world’s poor. This failure to effectively reach the most vulnerable populations has been, in part, a failure to develop and implement appropriate and effective primary care delivery models. This paper examines a root cause of these failures, namely that the inability to achieve clear and practical consensus around the scope and aims of primary care may be contributing to ongoing operational inertia. The present work also examines integrated models of care as a strategy to move beyond conceptual dissonance in primary care and toward implementation. Finally, this paper examines the strengths and weaknesses of a particular model, the World Health Organization’s Integrated Management of Adolescent and Adult Illness (IMAI), and its potential as a guidepost toward improving the quality of primary care delivery in poor settings. Discussion Integration and integrated care may be an important approach in establishing a new paradigm of primary care delivery, though overall, current evidence is mixed. However, a number of successful specific examples illustrate the potential for clinical and service integration to positively impact patient care in primary care settings. One example deserving of further examination is the IMAI, developed by the World Health Organization as an operational model that integrates discrete vertical interventions into a comprehensive delivery system encompassing triage and screening, basic acute and chronic disease care, basic prevention and treatment services, and follow-up and referral guidelines. IMAI is an integrated model delivered at a single point-of-care using a standard approach to each patient based on the universal patient history and physical examination. The evidence base on IMAI is currently weak, but whether or not IMAI itself ultimately proves useful in advancing primary care delivery, it is these principles that should serve as the basis for developing a standard of integrated primary care delivery for adults and adolescents that can serve as the foundation for ongoing quality improvement. Summary As integrated primary care is the standard of care in the developed world, so too must we move toward implementing integrated models of primary care delivery in poorer settings. Models such as IMAI are an important first step in this evolution. A robust and sustained commitment to innovation, research and quality improvement will be required if integrated primary care delivery is to become a reality in developing world

Ruthenocuprates RuSr2(Eu,Ce)2Cu2O10: Intrinsic magnetic multilayers

We report ac susceptibility data on RuSr_2(Eu,Ce)_2Cu_2O_(10-y) (Ru-1222, Ce content x=0.5 and 1.0), RuSr_2GdCu_2O_8 (Ru-1212) and SrRuO_3. Both Ru-1222 (x=0.5, 1.0) sample types exhibit unexpected magnetic dynamics in low magnetic fields: logarithmic time relaxation, switching behavior, and `inverted' hysteresis loops. Neither Ru-1212 nor SrRuO_3 exhibit such magnetic dynamics. The results are interpreted as evidence of the complex magnetic order in Ru-1222. We propose a specific multilayer model to explain the data, and note that superconductivity in the ruthenocuprate is compatible with both the presence and absence of the magnetic dynamics.Comment: 9 pages, 11 figures, Revtex; submitted to Phys.Rev.

Edible wild plant Heracleum pyrenaicum subsp orsinii as a potential new source of bioactive essential oils

Many Heracleum L. taxa (Apiaceae) are used as food and spices, and in traditional medicine. In this work, the chemical composition of Heracleum pyrenaicum subsp. orsinii (Guss.) F. Pedrotti and Pignatti root, leaf and fruit essential oils, their antimicrobial activity and cytotoxic effect on malignant and normal cells were investigated for the first time. The composition of the oils was analyzed by GC and GC-MS. Monoterpenes prevailed in the root oil, with beta-pinene (38.6%) being dominant, while in the leaf oil, sesquiterpenes, mostly (E)-nerolidol (20.5%) and (E)-caryophyllene (17.0%), were the most abundant constituents. The fruit oil contained the majority of aliphatic esters, mainly octyl acetate (36.8%) and octyl hexanoate (22.1%). The antimicrobial activity was determined by microdilution method against eight bacteria and eight fungi (standard strains, clinical or food isolates). The best antibacterial activity, better than the activity of ampicillin, was shown by the root oil against Salmonella typhimurium, Escherichia coli and Pseudomonas aeruginosa. The strongest antifungal activity, stronger than the activity of ketoconazole, was exhibited by the leaf and root oils against Trichoderma viride, and by the root oil against Aspergillus ochraceus. The cytotoxic effect of the oils, determined by MTT test, was prominent against malignant HeLa, LS174 and A549 cells (IC50 = 6.49-14.56 µg/mL). On the other hand, the oils did not show toxicity against normal MRC-5 cells at tested concentrations (IC50 > 200.00 µg/mL). It can be concluded that investigated H. pyrenaicum subsp. orsinii oils represent potential new raw materials for food and pharmaceutical industry