Unexpectedly Large Electron Correlation Measured in Auger Spectra of Ferromagnetic Iron Thin Films: Orbital-Selected Coulomb and Exchange Contributions.

A set of electron-correlation energies as large as 10 eV have been measured for a magnetic 2 ML Fe film deposited on Ag(001). By exploiting the spin selectivity in angle-resolved Auger-photoelectron coincidence spectroscopy and the Cini-Sawatzky theory, the core-valence-valence Auger spectrum of a spin-polarized system have been resolved: correlation energies have been determined for each individual combination of the two holes created in the four subbands involved in the decay: majority and minority spin, as well as e_{g} and t_{2g}. The energy difference between final states with parallel and antiparallel spin of the two emitted electrons is ascribed to the spin-flip energy for the final ion state, thus disentangling the contributions of Coulomb and exchange interactions.

Dynamic screening probed by core-resonant double photoemission from surfaces.

The universal response of a sudden created core hole, predicted to occur on an attosecond (10(-18) s) time scale, lacks an experimental demonstration. With a two-dimensional coincidence spectrometer, we demonstrate an extensive energy sharing between the Ag 4p photoelectron and the N2,3VV Auger electron exceeding 10 eV. This energy width provides access to the time scale of the emission process. This is the fingerprint of the dynamic fluctuation process 4p(-1)⇌4d(-2)4f. The shakeup induced interband transitions from the Ag(100) surface are also identified by comparing the coincidence spectrum with the M4,5VV Auger transitions.

Spin-dependent on-site electron correlations and localization in itinerant ferromagnets.

Spin selectivity in angle-resolved Auger photoelectron coincidence spectroscopy (AR-APECS) is used to probe electron correlation in ferromagnetic thin films. In particular, exploiting the AR-APECS capability to discriminate Auger electron emission events characterized by valence hole pairs created either in the high or in the low total spin state, a strong correlation effect in the Fe M(2,3)VV Auger line shape (measured in coincidence with the Fe 3p photoelectrons) of Fe/Cu(001) thin films is detected and ascribed to interactions within the majority spin subband. Such an assignment follows from a close comparison of the experimental AR-APECS line shapes with the predictions of a model based on spin polarized density functional theory and the Cini-Sawatzky approach.

Insight on hole-hole interaction and magnetic order from dichroic auger-photoelectron coincidence spectra.

The absence of sharp structures in the Auger line shapes of partially filled bands has severely limited the use of electron spectroscopy in magnetic crystals and other correlated materials. By a novel interplay of experimental and theoretical techniques we achieve a combined understanding of the photoelectron, Auger, and Auger-photoelectron coincidence spectra (APECS) of the antiferromagnetic CoO. A recently discovered dichroic effect in angle resolved (DEAR) APECS reveals a complex pattern in the Auger line shape, which is here explained in detail, labeling the final states by their total spin. Since the dichroic effect exists in the antiferromagnetic state but vanishes at the Néel temperature, the DEAR-APECS technique detects the phase transition from its local effects, thus providing a unique tool to observe and understand magnetic correlations where the usual methods are not applicable.

Concentrations of progesterone and a PGF2α metabolite during the interovulatory interval compared to the corresponding days of pregnancy in mares.

The concentrations of progesterone (P4) and a metabolite of PGF2α (PGFM) in mares were compared between the interovulatory interval (IOI; n = 8) and the corresponding days of pregnancy (n = 9). In daily blood samples, P4 increased between the day of ovulation (Day 0) and ∼Day 6 and then gradually decreased until the beginning of luteolysis in the IOI group. Before the beginning of luteolysis, there were no significant differences in P4 concentrations between the IOI and early pregnancy. In the IOI, PGFM concentration on the day before the beginning of luteolysis began to increase (P < 0.04) and reached a maximum mean (42.9 ± 11.6 pg/mL) on Day 14. In pregnancy, a novel increase in PGFM occurred from Day 12 to a maximum mean on Day 15 (16.7 ± 3.1 pg/mL). Daily PGFM concentrations were not different between the two groups until the increase just before luteolysis in the IOI. During 8-h sessions of hourly blood sampling, the mean and maximum PGFM concentrations were significantly greater in IOI than in pregnancy for each 8-h session on Days 13, 14, and 15. The minimum was not different between groups on any day. Pulses of PGFM were identified by coefficient of variation during the hourly 8-h sessions on day-sets of Days 4-7, 9-11, and 13-16. Despite the PGFM increase in daily samples between Days 12 and 15 of pregnancy, the amplitude and peaks of CV-identified pulses did not differ in the pregnant mares among the three day-sets. The pulses were similarly small for day-sets 4-7 and 9-11 in the IOI and for all day-sets in pregnancy (eg, amplitude on Days 13-16: 43.4 ± 15.6 pg/mL vs 5.4 ± 1.1 pg/mL for IOI vs pregnancy). Hypothesis 1 was not supported that daily PGFM concentrations in an IOI increase at the intersection between the end of the rapid P4 increase and the gradual P4 decrease. Hypothesis 2 was supported that pregnant mares have low amplitude PGFM pulses during the days of the high amplitude pulses at luteolysis in the IOI.

Nova-1 regulates neuron-specific alternative splicing and is essential for neuronal viability.

We have combined genetic and biochemical approaches to analyze the function of the RNA-binding protein Nova-1, the paraneoplastic opsoclonus-myoclonus ataxia (POMA) antigen. Nova-1 null mice die postnatally from a motor deficit associated with apoptotic death of spinal and brainstem neurons. Nova-1 null mice show specific splicing defects in two inhibitory receptor pre-mRNAs, glycine alpha2 exon 3A (GlyRalpha2 E3A) and GABA(A) exon gamma2L. Nova protein in brain extracts specifically bound to a previously identified GlyRalpha2 intronic (UCAUY)3 Nova target sequence, and Nova-1 acted directly on this element to increase E3A splicing in cotransfection assays. We conclude that Nova-1 binds RNA in a sequence-specific manner to regulate neuronal pre-mRNA alternative splicing; the defect in splicing in Nova-1 null mice provides a model for understanding the motor dysfunction in POMA.

Genetic component of sensitivity to heat stress for nonreturn rate of Brazilian Holstein cattle.

The objectives of the present study were: 1) to investigate variation in the genetic component of heat stress for nonreturn rate at 56 days after first artificial insemination (NR56); 2) to identify and characterize the genotype by environment interaction (G × E) due to heat stress for NR56 of Brazilian Holstein cattle. A linear random regression model (reaction norm model) was applied to 51,748 NR56 records of 28,595 heifers and multiparous cows. The decline in NR56 due to heat stress was more pronounced in milking cows compared to heifers. The age of females at first artificial insemination and temperature-humidity index (THI) exerted an important influence on the genetic parameters of NR56. Several evidence of G × E on NR56 were found as the high slope/intercept ratio and frequent intersection of reaction norms. Additionally, the genetic correlation between NR56 at opposite extremes of the THI scale reached estimates below zero, indicating that few of the same genes are responsible for NR56 under conditions of thermoneutrality and heat stress. The genetic evaluation and selection for NR56 in Holstein cattle reared under (sub)tropical conditions should therefore take into consideration the genetic variation on age at insemination and G × E due to heat stress.

Genetics of heat tolerance for milk yield and quality in Holsteins.

Tropical and sub-tropical climates are characterized by high temperature and humidity, during at least part of the year. Consequently, heat stress is common in Holstein cattle and productive and reproductive losses are frequent. Our objectives were as follows: (1) to quantify losses in production and quality of milk due to heat stress; (2) to estimate genetic correlations within and between milk yield (MY) and milk quality traits; and (3) to evaluate the trends of genetic components of tolerance to heat stress in multiple lactations of Brazilian Holstein cows. Thus, nine analyses using two-trait random regression animal models were carried out to estimate variance components and genetic parameters over temperature-humidity index (THI) values for MY and milk quality traits (three lactations: MY×fat percentage (F%), MY×protein percentage (P%) and MY×somatic cell score (SCS)) of Brazilian Holstein cattle. It was demonstrated that the effects of heat stress can be harmful for traits related to milk production and milk quality of Holstein cattle even though most herds were maintained in a modified environment, for example, with fans and sprinklers. For MY, the effect of heat stress was more detrimental in advanced lactations (-0.22 to -0.52 kg/day per increase of 1 THI unit). In general, the mean heritability estimates were higher for lower THI values and longer days in milk for all traits. In contrast, the heritability estimates for SCS increased with increasing THI values in the second and third lactation. For each trait studied, lower genetic correlations (different from unity) were observed between opposite extremes of THI (THI 47 v. THI 80) and in advanced lactations. The genetic correlations between MY and milk quality trait varied across the THI scale and lactations. The genotype×environment interaction due to heat stress was more important for MY and SCS, particularly in advanced lactations, and can affect the genetic relationship between MY and milk quality traits. Selection for higher MY, F% or P% may result in a poor response of the animals to heat stress, as a genetic antagonism was observed between the general production level and specific ability to respond to heat stress for these traits. Genetic trends confirm the adverse responses in the genetic components of heat stress over the years for milk production and quality. Consequently, the selection of Holstein cattle raised in modified environments in both tropical and sub-tropical regions should take into consideration the genetic variation in heat stress.

[Risks for construction workers: analysis of the upper limb posture]. / Rischi nel comparto edile: analisi della postura degli arti superiori.

Our work focuses on the analysis of risks associated with onset of cumulative trauma disorders (CTD) among construction workers, and the goal is to evaluate the different degree of involvement of articular segments of the upper limbs. A number of workers with different qualification were analyzed using the OCRA Index and check-list protocols, applied to highly or moderate repetitive activities. In order to evaluate the involvement of the various upper limbs segments, we have extracted the information contained in the "posture section" of the protocols, before they are grouped together in the final posture risk value, and analyzed them considering the observed working activities. We obtained an "involvement index" related to any of the upper limb segments, highlighting the information about local involvement during the various phases of work. This "involvement index" may help in analyzing and evaluating the ergonomic risk referring to each articular segment during activity, and can be useful in the analysis and prevention of work related CTDs.

The LVV Auger line shape of sulfur on copper studied by Auger photoelectron coincidence spectroscopy.

We have studied the line shapes of Cu(0 0 1)-p (2 × 2)S L2VV and L3VV Auger decay by means of Auger photoelectron coincidence spectroscopy. Measuring the LVV Auger spectrum in coincidence with S 2p1/2 and 2p3/2 photoelectrons respectively, we have been able to separate the two overlapping Auger spectra and determine their intrinsic line shapes. The two Auger transitions, though shifted in energy, display an identical line shape whose main features can be qualitatively understood considering a single particle approximation but are better described within a Cini-Sawatzky (CS) approach. Comparison between the experimental and the CS calculated spectra confirms that a substantial part of the Auger lines (∼20%) can be ascribed to decay events accompanied by the excitation of one additional electron-hole pair in the valence band. For the first time, the locality of the Auger process combined with the surface sensitivity of the APECS technique and its ability to separate overlapping structures are used to study Auger transitions taking place at the the surface states of a S/noble-metal interface.

LU52396, an inhibitor of the store-dependent (capacitative) Ca2+ influx.

The effects of 1-[2-(4-fluorophenyl)cyclohexyl]-2-[4-(3-phenylalkyl)-piperazin -1-yl]- ethanol, LU52396, on a) Ca2+ influx across the plasma membrane and b) Ca2+ mobilization from intracellular rapidly-exchanging Ca2+ stores were investigated in HeLa cells and in isolated microsomal fractions derived from the cerebellum and the skeletal muscle. LU52396 was found to be a potent inhibitor (Ki of about 2 microM) of the Ca2+ influx activated by depletion of intracellular Ca2+ stores, a phenomenon referred to as store-dependent or capacitative Ca2+ influx. Such an effect, which was reversed by cell washing, was mediated neither by a depolarization of the cell, with decrease in the driving force for cation influx, nor by a change of the intracellular pH, and might therefore be due to a direct action of the drug on either the responsible channel in the plasma membrane or, less likely, on its regulatory mechanisms. Additional effects, i.e. inhibition of receptor-mediated Ca2+ influx, of Ca2+ release from intracellular stores via either inositol 1,4,5-trisphosphate or ryanodine receptors, and of Ca2+ reuptake into the stores via sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPases, were also induced by the drug, however at concentrations 20-fold or more than those effective on the store-dependent influx. To our knowledge LU52396 is the first pharmacological tool that is found to be addressed with some preference to the store-dependent Ca2+ influx. It promises, therefore, to be useful for the characterization of the process, the identification of the responsible channel and, possibly, also of the molecular mechanisms through which these channels operate.

Steward's midline granuloma. A case report.

Steward's type of neoplastic disease is rare. Much has been discussed on the histopathology of this granuloma. Most authors define it as a neoplasm of the lymphoid system, and it is a subgroup of the "midline granuloma syndrome". We report a case of a 19-year-old first treated with chemotherapy (cyclophosphamide and prednisone) and then with radiotherapy, with good results.

[Acute abdomen as form of presentation of hepatic adenoma]. / Abdomen agudo como forma de presentación de un adenoma hepático.

We report the case of a woman aged 33 years old who was admitted with an acute abdomen. She referred oral contraceptives intake. Physical findings were abdominal tenderness, involuntary guarding and right upper quadrant rigidity. The following studies were performed: laboratory tests excluded hydatidosis and amebiasis. Ultrasonography showed a nodular image in the right hepatic lobe and a normal biliary tract. A low-density mass was observed with the computed tomographic scanning. A tomographic guided needle biopsy was informed as normal liver cells. Angiography showed tortuous hepatic arteries. Laparoscopy revealed a solid formation blood was obtained when it was punctured. Laparotomy was indicated. A tumor in the right hepatic lobe was found but a surgeon did not resect the lesion because a congelation biopsy failed to demonstrate tumoral cells. The diagnosis of hepatic adenoma was reached with the definitive biopsy. Our patient had a good evolution with the contraceptives withdrawal and a tomographic scanning one year after surgery showed the almost complete remission of the tumor. Pain as the initial symptom was observed in 12-52% of patients with an hepatic adenoma an audden onset in 33% of them. However this tumor is not frequently considered as a cause of acute abdomen.

PIP: The case is described of a 33-year-old woman with an 8-year history of oral contraceptive (OC) use who was treated at a hospital in Buenos Aires for a hepatic adenoma. The woman was admitted with an acute abdomen. Apart from OC use she had a history of hypertension for which she was treated with clonidine and diuretics. The physical findings included pain in the right abdomen, involuntary guarding, vomiting, and fever. Ultrasonography showed a normal bladder and pancreas and a nodular image in the right hepatic lobe. A CAT scan revealed a mass in the right hepatic lobe, and a needle biopsy later showed normal hepatic cells. Laparoscopy revealed a solid formation from which blood was obtained on puncturing. Angiography showed tortuous hepatic arteries. Laboratory tests were normal. An exploratory laparotomy was performed when the different studies failed to establish a clear diagnosis. A tumor was found in the right hepatic lobe but was not respected because the frozen section biopsy did not show malignant cells. The definite diagnosis of hepatic adenoma was based on the definitive biopsy. OC treatment was terminated and the tumor was in almost complete remission 1 year later. Hepatic adenomas are benign tumors, usually single, which occur rarely and primarily in women aged 30-40 who use OCs. A review of the literature indicated that the forms of presentation of hepatic adenoma are very varied. Pain was the initial symptom in 12-52% of cases. The pain was of sudden onset in 1/3. Hepatic adenoma is however infrequently considered as a cause of acute abdomen. Treatment in 73% of cases is surgical because of the danger of hemorrhage and shock and because of the potential for malignant transformation.

[Fever as periodic disorder]. / La febbre come disturbo periodico.

Slight, moderate but also high rises in temperature, excluding other causes of fever, can be considered symptoms of periodic syndrome originating by hypothalamic centers as soon as headache, recurrent abdominal pains, growing pains, dizziness, kinetosis. These rises aren't uncommon, but often aren't considered important and this few statistics are available. The Authors present 16 case reports of fever as periodic symptom and discuss how common factors exist in the mechanism of hyperthermia and other clinical signs of periodic syndrome (ex. migraine) but they are generally modulated differently so that disturbance of temperature regulation predominates in the first case, pain in the second.

[A diagnostic controversy: the significance of 14-6/sec positive spikes in clinical electroencephalography]. / Un problema controverso: il significato delle punte positive di 14-6 c/sec nella elettroencefalografia clinica.

There has been a great dealt of discussion as to the clinical significance of E.E.G. 14-6 per second positive spikes (14-6 PS), a short burst lasting one second or less which occurs during light sleep in monopolar recordings, mainly in the posterior temporal regions and usually involving the parietal and occipital regions as well, for the most part in unsymmetrical fashion. Early interpretations stress the epileptic nature of vegetative attacks in patients with an inter-critical E.E.G. reading characterized by 14-6 P.S. Subsequently, however, this hypothesis has been refuted, mainly because E.E.G. intra-critical recordings have never shown evidence of any sort of paroxysmal activity. At present time expert think that the presence of 14-6 PS may be merely an indication of an electrical alteration associated with disorders in the neurovegetative area. In order to evaluate the possibility of using them as a diagnostic marker of migraine equivalents and periodic syndromes, we reviewed wake and sleep E.E.G. recordings, carried out consecutively and hence not selectively, in 617 children aged 5-16 years. 14-6 PS were present in 109 children (17.6%), 63 of whom showed evident symptoms of periodic syndrome (headache, recurrent abdominal pain, cyclic vomiting, kinetosis, etc.); hence 46 E.E.G. recording were false positive. 510 children were lacking in 14-6 PS, 91 of these presented symptoms of periodic syndromes (false negative). 14-6 PS are hence a marker 40.9% sensitive, 90.1% specific, with a predictable value of 57.7%. The search for 14-6 PS in children with periodic syndrome is not particularly sensitive as a test, but it is fairly specific: it may well constitute an useful element in diagnosis.

[Thrombophlebitis of the cavernous sinus and inappropriate ADH secretion syndrome]. / Tromboflebite del seno cavernoso e sindrome da inappropriata secrezione di ADH.

The septic thrombosis of the cavernous sinus is a rare and serious disease which still occurs occasionally. The physician should be aware of this fact when treating infections of the nasal orbital areas. A case is presented in whom the septic thrombosis of the cavernous sinus is associated with the syndrome of inappropriate secretion of antidiuretic hormone.

[Magnesium in the prophylaxis of primary headache and other periodic disorders in children]. / Il magnesio nella profilassi della cefalea primaria e di altri disturbi periodici del bambino.

Migraine has been recently defined a "central neuronal hyperexcitability state", maybe magnesium-dependent, and magnesium has been occasionally employed in the therapy of adult migraine. The Authors, on the basis of their personal experience (previous electromyographic studies), consider childhood migraine and periodic syndrome as a clinical equivalent of spasmophilia, in which an intracellular deficit of magnesium has been demonstrated, and have employed a magnesium salt in the prophylaxis of childhood migraine and migraine equivalents. 40 children with periodic syndrome (17 M and 23 F, aged 10.4 +/- 2.9 years) have been treated with magnesium pidolate, with doses ranging from 1.5 g/die to 4.5 g/die (corresponding to 122-366 mg Mg++):25 of them presented migraine as the main symptom, 12 recurrent abdominal pain, 3 fever of unknown origin, along with many other periodic symptoms. The first control visits have been done at 1 month, clinical follow-up lasted a mean period of 6.1 months. Therapy was stopped at 1 month visit if ineffective (of some other drug was added); otherwise, magnesium therapy was continued with the same dosage for another month, then gradually reduced. Clinical response was considered good if crises ceased completely or their frequency was reduced to less than 33%; partial if reduced to less than 67% of previous incidence; absent if only slightly or not at all reduced. Clinical response was good in 72.5% of cases at 1 month, in 77.5% later; partial in 12.5% and 10%; absent in 15% and 12.5% respectively. No side effects were observed. The compliance of children and their families was complete.(ABSTRACT TRUNCATED AT 250 WORDS)

[Neurocysticercosis: a rare cause of convulsive crises]. / Neurocisticercosi. Una rara causa di crisi convulsive.

The cysticercosis is an infestation caused from the larva of Taenia solium, which is demoniated Cysticercus cellulosae. Infestation by the encysted forms occur within brain, muscle, cutis, eye and more rarely within kidney, liver, thyroid. The cysties cause inflammation, oedema and residual calcification. In the SNC they are responsible for seizures, usually of focal type, hydrocephalus, meningitis, endocranic hypertension, stroke. One case of neurocysticercosis in a 15 years old boy is described: the clinical pictures, the neuroradiologic images and the treatment are discussed.

The attenuation length of low energy electrons in Yb.

Photoelectron emission spectra in a photon energy range between 7.5 and 21 eV are measured for in situ grown polycrystalline Yb films. By comparing bulk and surface core level shifted 4f components we give an estimation of the effective attenuation length (EAL) for low energy (6-20 eV) electrons in Yb, establishing a moderate increase of the EAL upon electron energy decrease. The experimental EAL data are found to be a factor of four smaller than those predicted from the so-called 'universal curve'.