Characterization of femtosecond laser written waveguides for integrated biochemical sensing

Fluorescence detection is known to be one of the most sensitive among the different optical sensing techniques. This work focuses on excitation and detection of fluorescence emitted by DNA strands labeled with fluorescent dye molecules that can be excited at a specific wavelength. Excitation occurs via optical channel waveguides written with femtosecond laser pulses applied coplanar with a microfluidic channel on a glass chip. The waveguides are optically characterized in order to facilitate the design of sensing structures which can be applied for monitoring the spatial separation of biochemical\ud species as a result of capillary electrophoresis

Effects of native plants extracts from Córdoba Argentina over foraging activity of the cutting ant Acromyrmex lundi (Guérin)

In the search for new alternatives for insect pest management, natural products from plants are an option currently studied for being substances of low toxicity and biodegradable. The leaf-cutting ant Acromyrmex lundi is a very important herbivorous species in the Argentine Chaco phytogeographic region as it can cut various parts of plants and attack almost all cultivated species. The objectives of this study were: 1. determine the effect of plant extracts native of Córdoba-Argentina on the foraging activity of A. lundi in an artificial nest. 2. evaluate the crude extract with highest activity in foraging activity field tests. Extracts were prepares with aerial parts of plants belonging to 28 botanical families. In the laboratory, an artificial nest was installed, which consisted of a main chamber where the queen, the immature and the fungus remained, and smaller chambers that operated as dump and foraging areas. The work was carried out under controlled conditions (27°C, 12:12 hs light/darkness and Hº 25± 3). In free-choice tests, 8 discs of rose leaves of 1 cm of diameter were impregnated with 10μl per cm2 of a 1% solution (10 ug / ul) of each extract or solvent (control). The Inhibitory Dose 50 (ID50) was determined for all the extracts that showed 100% repellency. Aristolochia argentina Griseb. showed the lowest DI50 values, for what it was chosen for field trials. Rose leaves treated with A. argentina extract (1% and 5%) and others with acetone (control) were placed on either side of an actively foraging path of six active nests of A. lundi, 50cm from the nest opening. The percentage of removed material was registered within two hours of observation and on two consecutive days, ending the trial when removed 50% of the total substrate provided. Also, foraging activity was determined by counting at a fixed point and for a period of three minutes, the number of workers who went towards the mound charged. In field trials, the 1% extract of A. argentina (n = 6) did not affect foraging activity (P> 0.05), whereas the 5% dose (n = 5) showed significant differences between treatments (P <0.05). From these preliminary results, future studies arise to deepen different effects of the compound oriented to leaf-cutting ants management.Fil: Nolli, L.C. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Nolli, L.C. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Buffa, L.M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Buffa, L.M. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Defagó, M. T. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Entomología; Argentina.Fil: Defagó, M. T. Centro de Investigaciones Entomológicas de Córdoba; Argentina.Fil: Diaz Napal, G. Universidad Católica de Córdoba. Facultad de Ciencias Químicas. Laboratorio de Química Fina y Productos Naturales; Argentina.Fil: Palacios, S. M. Universidad Católica de Córdoba. Facultad de Ciencias Químicas. Laboratorio de Química Fina y Productos Naturales; Argentina.Zoología, Ornitología, Entomología, Etologí

Separation and characterization of nonphosphorylated and serine-phosphorylated urokinase. Catalytic properties and sensitivity to plasminogen activator inhibitor type 1.

Urokinase synthesized by human A431 epidermoid carcinoma cells is phosphorylated on serine (Mastronicola, M. R., Stoppelli, M. P., Migliaccio, A., Auricchio, F., and Blasi, F. (1990) FEBS Lett. 266, 109-114). To test the possibility that phosphorylation may have specific effects on urokinase function, the phosphorylated and nonphosphorylated forms of urokinase were separated by Fe(3+)-Sepharose chromatography. Both forms exhibit indistinguishable Km and kcat for plasminogen activation. On the other hand, their sensitivity toward the specific plasminogen activator inhibitor type 1 is different as assessed by measuring both the stability of the covalent complex and the residual enzymatic activity. Phosphorylated urokinase was 50% inhibited at a concentration of plasminogen activator inhibitor type 1 4-fold higher than nonphosphorylated urokinase (0.7 versus 0.15 nM). Furthermore about 10% of phosphorylated urokinase was resistant to plasminogen activator inhibitor type 1 at a concentration as high as 20 nM. Thus, phosphorylation affects urokinase sensitivity to plasminogen activator inhibitor type 1, therefore resulting in a net, although indirect, increase of urokinase activity. These results suggest the existence of a novel cellular regulatory mechanism of extracellular proteolysis

Compact setup for the production of Rb-87 vertical bar F=2, m(F) =+2 > Bose-Einstein condensates in a hybrid trap

We present a compact experimental apparatus for Bose-Einstein condensation of 87Rb in the |F  =  2, mF = + 2〉 state. A pre-cooled atomic beam of 87Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trap depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the |F = 2, mF = + 2〉 state in 50 s, which includes 33 s loading of the science magneto-optical trap and 17 s forced evaporation

A recessive homozygous p.Asp92Gly SDHD mutation causes prenatal cardiomyopathy and a severe mitochondrial complex II deficiency

Succinate dehydrogenase (SDH) is a crucial metabolic enzyme complex that is involved in ATP production, playing roles in both the tricarboxylic cycle and the mitochondrial respiratory chain (complex II). Isolated complex II deficiency is one of the rarest oxidative phosphorylation disorders with mutations described in three structural subunits and one of the assembly factors; just one case is attributed to recessively inherited SDHD mutations. We report the pathological, biochemical, histochemical and molecular genetic investigations of a male neonate who had left ventricular hypertrophy detected on antenatal scan and died on day one of life. Subsequent postmortem examination confirmed hypertrophic cardiomyopathy with left ventricular non-compaction. Biochemical analysis of his skeletal muscle biopsy revealed evidence of a severe isolated complex II deficiency and candidate gene sequencing revealed a novel homozygous c.275A>G, p.(Asp92Gly) SDHD mutation which was shown to be recessively inherited through segregation studies. The affected amino acid has been reported as a Dutch founder mutation p.(Asp92Tyr) in families with hereditary head and neck paraganglioma. By introducing both mutations into Saccharomyces cerevisiae, we were able to confirm that the p.(Asp92Gly) mutation causes a more severe oxidative growth phenotype than the p.(Asp92Tyr) mutant, and provides functional evidence to support the pathogenicity of the patient’s SDHD mutation. This is only the second case of mitochondrial complex II deficiency due to inherited SDHD mutations and highlights the importance of sequencing all SDH genes in patients with biochemical and histochemical evidence of isolated mitochondrial complex II deficiency

INTRODUZIONE AL CONCETTO DI INTEGRALE: LA FISICA “AL SERVIZIO” DELLA MATEMATICA?

Si descrive e si discute una esperienza didattica nella quale l'uitilizzo di un problema di fisica è risultato centrale nel motivare e supportare gli alunni nel raggiungimento della comprensione di un concetto chiave dei programmi di matematica: il concetto di integrale definito

Metabolic effects of liposuction- yes or no?

Klein et al. report that abdominal liposuction in 15 overweight women did not produce any significant change in metabolic abnormalities associated with obesity. We analyzed the metabolic effects of ultrasound-assisted megalipoplasty in eight premenopausal obese women (mean [\ub1SD] body-mass index [the weight in kilograms divided by the square of the height in meters], 42.0\ub17.0). Measurements of body composition with dual-energy x-ray absorptiometry, insulin resistance (with the homeostasis-model assessment method),1 leptin, C-reactive protein, interleukin-6, resistin, and adiponectin were taken before and 1, 3, 28, and 180 days after ultrasound-assisted megalipoplasty. Ultrasound-assisted megalipoplasty reduced fat mass from 48.9\ub110.2 kg to 41.0\ub18.1 kg at day 3, and no further changes were seen. The greatest amounts of fat were removed from the lower limbs. The changes in insulin resistance and cytokine levels after the procedure are depicted in Figure 1Figure 1Insulin Resistance and Cytokine Levels in Eight Premenopausal Obese Women with Peripheral Fat Distribution, before and after Ultrasound-Assisted Megalipoplasty (UAM).. An acute reduction in insulin sensitivity occurred postoperatively, with related changes in the adipocytokines involved in insulin action. In the recovery phase, we observed improvement in insulin resistance in association with a reduction in leptin levels, consistent with loss of fat mass, as reported by others.2 We suggest that the metabolic effects of ultrasound-assisted megalipoplasty may be influenced by fat distribution and the length of follow-up

Luce, colore e visione

Il contributo si rivolge a ricercatori in didattica della fisica e ad insegnanti di area scientifica dei diversi livelli scolastici. Presenta delle linee-guida, che coniugano riflessioni a livello disciplinare e indicazioni a carattere didattico, per affrontare lo studio dell'ottica in una visione longitudinale dell'insegnamento scientifico lungo tutto l'arco scolastico pre-universitario. Un primo paragrafo \ue8 dedicato alla presentazione della struttura concettuale del tema affrontato, considerato prevalentemente dal punto di vista della fisica. Il versante disciplinare e il versante cognitivo sono strettamente intrecciati all'interno di una visione dell'azione didattica come mediazione continua fra la rete concettuale disciplinare e la rete cognitiva (idee, esperienze, modi di ragionare, agire, comunicare ecc...), in continua evoluzione, di ciascuno e di tutti gli allievi. Un secondo paragrafo presenta gli elementi di una possibile linea di sviluppo verticale del tema Luce dalla scuola dell'inafanzia al termine della scuola secondaria di secondo grado, a partire da un argomento specifico (lo studio delle ombre). Questa parte vuole mostrare la possibilit\ue0 di costruire un percorso, con carattere di continuit\ue0, in cui il lavoro ad ogni livello scolastico sia un elemento di avanzamento rispetto ai livelli precedenti e la base rispetto ai livelli successivi. Un terzo paragrafo, infine, fornisce alcuni suggerimenti per iniziare ad orientarsi tra le numerose proposte didattiche disponibili in rete. Completano il contributo inserti tratti da materiale prodotto in sperimentazioni di classe e due allegati, il primo dei quali sviluppa il tema della modellizzazione in fisica, mentre il secondo presenta un percorso didattico illustrato nel "diario di bordo" di un insegnante, commentandone gli aspetti di mediazione didattica