Pregnancy and internet: sociodemographic and geographic differences in e-health practice. Results from an Italian multicenter study.

OBJECTIVES: Since the new millennium, the number of e-health users has significantly increased. Among these, a particular category of people who are interested by this phenomenon is the one of pregnant women. The aim of the present study is to assess the sociodemographic and geographic differences existing in a sample of Italian pregnant women who search for information on the web. STUDY DESIGN: Multicenter cross-sectional survey. METHODS: The present study has been conducted from November 2011 to September 2012, in seven Italian cities, located in the North, in the Centre and in the South of Italy. Data were collected through an anonymous questionnaire, administered in waiting rooms of outpatient departments by trained medical doctors. Data were analysed through multivariate logistic regression models. RESULTS: Overall, 1347 responders were interviewed. Eighty-six percent of them declared to surf the internet to retrieve pregnancy-related information. The most searched topics were fetal development (51.3%), healthy lifestyle during pregnancy (48.7%), physiology of pregnancy (39.8%), generic and specific tips/advices during pregnancy (37.2%) and lactation (36.8%). Statistically significant differences (P < 0.05) according to geographic origin, age and educational level were found with regard to the most frequently searched information on the Web, the reasons that pushed pregnant women to practice e-health, and the possibility to change lifestyles after e-health. CONCLUSIONS: Our findings suggest that the phenomenon of pregnancy e-health is widespread and show social and geographic differences, in particular about city of residence, age and educational level. It might encourage healthcare professionals to be more available and exhaustive during routine visits and to be more careful about web content on this topic, also addressing the different needs into different geographic contexts.

[Respiratory and physical recovery in cervical spinal cord injury. Seventeen years' experience in a weaning and rehabilitation center: An observational study]. / Evolución respiratoria y motora en lesión medular cervical. Diecisiete años de experiencia en un centro de desvinculación de asistencia ventilatoria mecánica: un estudio observacional.

INTRODUCTION AND OBJECTIVES: Spinal cord injury (SCI) is a devastating entity that generates substantial disability. The outcome of respiratory and motor features has an impact in human and social well-being. We analyzed demographic characteristics, motor and respiratory outcomes, and determined equipment needs at discharge in a weaning and rehabilitation center. MATERIAL AND METHOD: Observational, descriptive and retrospective study of medical records between January 2002 and December 2018. Tracheostomised cervical SCI patients with invasive mechanical ventilation were included. Forced vital capacity (upright and supine), maximal inspiratory and expiratory pressures, ASIA and Spinal Cord Independence MeasureIII (SCIMIII) were obtained. RESULTS: Of 1603 patients, 3.5% had SCI, and 28 met the inclusion criteria. The most frequent level of injury was C4-C5 (17/28), 21/28 had ASIAA classification, and 19 showed no change in either the ASIA or the SCIM score. In all, 22/28 patients were weaned, while 15/28 were decannulated. Twenty four patients were discharged to home. The most relevant change in SCIMIII was in the 5th component of respiration and sphincter subscale, related to weaning and tracheostomy. At discharge, 23/24 patients needed both respiratory and motor aids. CONCLUSIONS: The admission rate of SCI patients was low in our weaning and rehabilitation center, with almost all being admitted for traumatic causes. Severity remained unchanged in most ASIAA patients. Respiratory recovery was more clinically significant than recovery of motor function. Upon discharge, most of our patients had to be equipped with both respiratory and motor aids.

[Role of the Web on behaviors and health choices in six Italian cities: results of a multicenter study]. / Ruolo del web sui comportamenti e sulle scelte sanitarie in sei città italiane: risultati di uno studio multicentrico.

A cross-sectional, multicenter study was carried out in 6 Italian cities (Cassino, Chieti, Naples, Rome, Siena, Turin) in order to highlight differences in Web use to find out health information and its related consequences on behavioral choices and to describe the distribution of the phenomenon in Italy. Data were collected from October 2009 to September 2010 on a sample of volunteers recruited from laboratory analysis, with face-to-face interview, including information about socio-demographic, health, and Web use to health. Data analysis shows that e-health use is greater in Northern Italy, in women aged 30-41 years, in chronic patients and those who have been caught up medical malpractice. Behavioral changes are associated with the Region; in particular Rome and Cassino show to choose/change professionals and facilities, engaging in alternative therapies and buy drugs online more frequently. Living in Southern Italy, a lower educational level and the infrequent drugs use are associated with a greater probability of incurring in negative behaviors. Positive results on the behavior are instead low and not significant. Given the regional differences, the potentiality and the risks of e-health use, it will be important to identify strategies for risks containment and implementation of the web in prevention.

Central drive and ventilatory failure in late-onset Pompe disease: At the gates of a new phenotype.

Subjects with late-onset Pompe disease (LOPD) typically present as slowly progressive proximal muscle weakness. Respiratory muscle weakness and diaphragmatic paralysis are common features, and may be the initial manifestation of the disease. There is often a poor correlation between the severity of limb and respiratory muscle weakness. Early clinical observations about disproportionate hypercapnia to the respiratory muscular weakness in late-onset Pompe disease were recognized and will be discussed with special reference to blunted respiratory drive, and the connections between early clinical observations, respiratory functional studies and anatomical findings. According to new evidence about blunted respiratory drive in Pompe disease, it is necessary to rethink what is meant by "asymptomatic Pompe disease" and propose a new phenotype with its therapeutic implications. The conceptual model of the mechanisms leading to respiratory failure in this disease could be considered according to these new findings. It may broaden the diagnostic spectrum of the adult forms and warrants a closer interaction between neurologists and pulmonologists. The recognition of this new phenotype of predominant central alveolar hypoventilation in Pompe disease will improve the understanding of the underlying mechanisms of ventilatory failure and could lead to improved future therapeutic strategies.

Spectral algorithms for supervised learning.

We discuss how a large class of regularization methods, collectively known as spectral regularization and originally designed for solving ill-posed inverse problems, gives rise to regularized learning algorithms. All of these algorithms are consistent kernel methods that can be easily implemented. The intuition behind their derivation is that the same principle allowing for the numerical stabilization of a matrix inversion problem is crucial to avoid overfitting. The various methods have a common derivation but different computational and theoretical properties. We describe examples of such algorithms, analyze their classification performance on several data sets and discuss their applicability to real-world problems.

Preventable infectious diseases using vaccination in developmental age in the province of Frosinone, Italy.

INTRODUCTION: A study has been made of the behaviour of preventable infectious diseases by means of vaccination in the developmental age, reported between 1995 and 2003, in the area of Frosinone and Province, Italy. RESULTS: . Analysis of the distribution of the 185 cases of hepatitis B notified, demonstrates that the mean age has increased from 26.5 to 41.1 years. Notifications of invasive diseases due to haemophilus influenzae type b (Hib) refer exclusively to 13 cases of meningitis. As far as concerns pertussis, 119 cases have been reported (median age 4.0 years, mode 1.0). Overall 850 cases of measles were reported (median age 7.0 years, mode 5.0), the highest number being recorded in 1997 (349 cases: median age 7.0 years, mode 5.0) and 2002 (199 cases: median age 8.0 years, mode 8.0). Rubella occurred in 411 cases (median age 12.0 years, mode 11.0), with 53.3% involving females. As far as concerns mumps, the last peak of the epidemic occurred in 2001 (median age 7.0 years, mode 6.0) with 137 cases. DISCUSSION AND CONCLUSION: Results emerging from the study demonstrate a reduction in time in the number of notifications for almost all the diseases under consideration. The distribution of the cases of rubella infertile females, in 2002, stresses the need to promote campaigns in order to recuperate still-susceptible women of childbearing age. The cases of hepatitis B, pertussis and meningitis due to Hib confirm the high rate of protection resulting from vaccination. The incidence rates of measles, mumps, rubella and pertussis when compared with those of the paediatric sentinel surveillance system (SPES) clearly demonstrate not only that these are underestimated but also reveal controversial findings with respect to data provided by Infectious Diseases Italian Surveillance System (SIMI).

[Survey of the presence of Listeria monocytogenes in meat products sold in retail]. / Indagine sulla presenza di Listeria monocytogenes in prodotti carnei venduti al dettaglio.

The present study evaluates the presence of Listeria spp and particularly of L. monocytogenes in bovine, pork and poultry meats sold by retail in supermarkets and butchers in the city of Cassino. The sensibility to the antibiotics mostly used in the veterinary practice has been tested on the isolated strains. The different species of Listeria have shown a considerable variation of isolation based on the meat's typology and on the different store's provenance. Moreover our results show greater degree of contamination than the data currently available the Italian literature. In our study poultry meat is the most contaminated one. We can assert that omissions and poor caring errors in the manipulation and conservation of meat expose the customer to an even higher risk of infection.

Evolución respiratoria y motora en lesión medular cervical. Diecisiete años de experiencia en un centro de desvinculación de asistencia ventilatoria mecánica: un estudio observacional / Respiratory and physical recovery in cervical spinal cord injury. Seventeen years’ experience in a weaning and rehabilitation center: An observational study

Introducción y objetivos: La lesión medular (LM) es una entidad devastadora que genera importante discapacidad. La evolución motora y la respiratoria tienen impacto humano y social. Se analizaron aspectos demográficos, evolución respiratoria, motora y el equipamiento necesario al alta en un centro de desvinculación de ventilación mecánica y rehabilitación (CDVMR). Materiales y métodos: Estudio observacional, descriptivo y retrospectivo de historias clínicas entre enero de 2002 y diciembre de 2018. Se incluyeron pacientes con LM cervical, traqueostomía y ventilación mecánica invasiva. Se obtuvieron: capacidad vital forzada (sedestación, decúbito supino), presiones inspiratorias y espiratorias máximas, ASIA y Spinal Cord Independence MeasureIII (SCIMIII). Resultados: De 1.603 pacientes, el 3,1% tenían LM y 28 reunieron el criterio de inclusión. Los niveles más frecuentes (17/28) fueron C4-C5, 21/28 tenían ASIAA, 19 no cambiaron el grado de lesión ni la puntuación en el SCIMIII. Fueron desvinculados 22/28 pacientes y 15/28 fueron decanulados. Veinticuatro pacientes alcanzaron el alta domiciliaria. El mayor cambio en el SCIMIII fue en el componente5 del dominio respiración y manejo esfinteriano, relacionado exclusivamente con la desvinculación del ventilador y la presencia de traqueostomía. Al alta, 23/24 pacientes fueron equipados con dispositivos de asistencia respiratoria y motora. Conclusiones: Las LM representan un bajo porcentaje de admisión a CDVMR, y casi la totalidad fueron de origen traumático. La mayoría de los pacientes con ASIAA permanecieron en el mismo grado de severidad. La evolución respiratoria tuvo mayores cambios, mientras que la motora presentó cambios marginales. Al alta, la mayoría de nuestros pacientes necesitaron equipamiento motor y respiratorio.(AU)

Introduction and objectives: Spinal cord injury (SCI) is a devastating entity that generates substantial disability. The outcome of respiratory and motor features has an impact in human and social well-being. We analyzed demographic characteristics, motor and respiratory outcomes, and determined equipment needs at discharge in a weaning and rehabilitation center. Material and method: Observational, descriptive and retrospective study of medical records between January 2002 and December 2018. Tracheostomised cervical SCI patients with invasive mechanical ventilation were included. Forced vital capacity (upright and supine), maximal inspiratory and expiratory pressures, ASIA and Spinal Cord Independence MeasureIII (SCIMIII) were obtained. Results: Of 1603 patients, 3.5% had SCI, and 28 met the inclusion criteria. The most frequent level of injury was C4-C5 (17/28), 21/28 had ASIAA classification, and 19 showed no change in either the ASIA or the SCIM score. In all, 22/28 patients were weaned, while 15/28 were decannulated. Twenty four patients were discharged to home. The most relevant change in SCIMIII was in the 5th component of respiration and sphincter subscale, related to weaning and tracheostomy. At discharge, 23/24 patients needed both respiratory and motor aids. Conclusions: The admission rate of SCI patients was low in our weaning and rehabilitation center, with almost all being admitted for traumatic causes. Severity remained unchanged in most ASIAA patients. Respiratory recovery was more clinically significant than recovery of motor function. Upon discharge, most of our patients had to be equipped with both respiratory and motor aids.(AU)

Reliability of adapted version of Italian Label tobacco Impact Index for the adolescent: ALII.

OBJECTIVE: The aim of this study is to assess the reliability of the Adolescent Label Impact Index (ALII) , it is an adolescent adapted version of Italian LII of the tobacco products warnings. MATERIAL AND METHODS: A sample including students aged 13-15 years was considered. The ALII is constructed by 4 items: salience, harm, quitting and forgo. The questionnaire was self-administered to study participants twice with 3 days between each administration (T1 and T2) to measure reliability. The internal consistency using Cronbach's alpha and Corrected Item-Total Correlations (CITC) and the test-retest reliability applying Pearson's correlation were computed. RESULTS: Cronbach's alpha ranges from 0.625 at T1 to 0.715 at T2. The "salience" resulted the item with the lowest CITC value (=0.281). The Pearson's coefficient was r=0.909 (p<0.001). CONCLUSIONS: The instruments is low in cost and easy to administer and analyses in a setting people aged 13-15 years. The ALII shown an acceptable consistency and excellent stability over time. However, attention has to be paid when the ALII is administered to the no smoking teens and who has never seen the tobacco product labels to allow an appropriate interpretation of the data collected.

Alter Ego. Drug and brain--information to prevent. Compared analysis of opinions, knowledge and habits among a multicentric sample of secondary school students about drug addiction.

Repression and control have been shown to be inadequate for drug addiction issues. Recent history, however has proved that information is one of the most effective measures against the spread of drugs. The wide range of drug circulation and the need for the spread of correct information on the effects of drugs in man, especially his brain, have led the Center for Scientific Culture Diffusion of Cassino University, to widen the scope of "Alter Ego. Drugs and the brain", a touring educational exhibition, which opened in 1994, by dedicating more attention to socially accepted drugs, such as alcohol and tobacco, and to new substances like ecstasy and similar drugs. Concurrently with the Alter Ego touring exhibition, a study was undertaken to obtain information on public awareness of the dangers of psychotropic drug abuse and to assess the effectiveness of the exhibition as an instrument of scientific information about drug addiction among its visitors, during its tour of over 60 Italian towns.

[The childhood home accidents: risk perception and behavior].

OBJECTIVE: The aim of the study was to assess the frequency and the kind of home injuries among the children and to have information on the sources of risk and hazardous behaviors in the home setting. METHODS: An anonymous questionnaire was administered to parents. In order to evaluate the risk perception in relation to the home environment, drawings to color were administered to children in kindergarten and to those of the first cycle of elementary school. A questionnaire was administered to older pupils. Statistical analyses were performed using the statistical program EPIINFO. RESULTS: The most risky behaviors showed by about half of parents were to cook lunch and doing other works in the house, cook with children in the kitchen. 28.0% said that sometimes left unattended appliances. Discordant opinions were found on the possibility of having injuries at home, in fact, 39.7% of parents affirmed that their son was victim of a home injury, compared with 64.0% of children. The number of children victims of home injuries was significantly higher among those aged between 6 and 10 years. DISCUSSION: Our search was in according with the national trend of the types and outcomes of home injuries, and confirms the existence of relationship between low educational level and higher frequency of injuries in childhood. Although prevention was considered an invaluable tool by parents to ensure the child's safety from the earliest years of life in this way, this study highlights the urgent need to take preventive action to develop an adequate safety culture.

Multiprobe Study of the Solid Electrolyte Interphase on Silicon-Based Electrodes in Full-Cell Configuration.

The failure mechanism of silicon-based electrodes has been studied only in a half-cell configuration so far. Here, a combination of 7Li, 19F MAS NMR, XPS, TOF-SIMS, and STEM-EELS, provides an in-depth characterization of the solid electrolyte interphase (SEI) formation on the surface of silicon and its evolution upon aging and cycling with LiNi1/3Mn1/3Co1/3O2 as the positive electrode in a full Li-ion cell configuration. This multiprobe approach indicates that the electrolyte degradation process observed in the case of full Li-ion cells exhibits many similarities to what has been observed in the case of half-cells in previous works, in particular during the early stages of the cycling. Like in the case of Si/Li half-cells, the development of the inorganic part of the SEI mostly occurs during the early stage of cycling while an incessant degradation of the organic solvents of the electrolyte occurs upon cycling. However, for extended cycling, all the lithium available for cycling is consumed because of parasitic reactions and is either trapped in an intermediate part of the SEI or in the electrolyte. This nevertheless does not prevent the further degradation of the organic electrolyte solvents, leading to the formation of lithium-free organic degradation products at the extreme surface of the SEI. At this point, without any available lithium left, the cell cannot function properly anymore. Cycled positive and negative electrodes do not show any sign of particles disconnection or clogging of their porosity by electrolyte degradation products and can still function in half-cell configuration. The failure mechanism for full Li-ion cells appears then very different from that known for half-cells and is clearly due to a lack of cyclable lithium because of parasitic reactions occurring before the accumulation of electrolyte degradation products clogs the porosity of the composite electrode or disconnects the active material particles.

[Applicability of the new law of State and Regional Agreement on management of swimming pools]. / Applicabilità del nuovo Atto di Intesa Stato-Regioni per la gestione degli impianti natatori.

The Authors carried out a survey on private and public managers of 80 Italian swimming pools to evaluate the hygienic aspects and safety of the swimming pools. Participants were submitted to a set of questions about the modifications recently brought to the Act on management of the swimming pools during 2003. The study showed a poor knowledge about the hygienic-safety parameters, in particular of chlorine doses, range of temperature and frequency of daily turnover of the swimming pool water. The respect of chemical-physical parameters is necessary not only to assure an adequate microbial control of the water, but also to reduce the production of irritant and potentially toxic substances. The Authors pointed out the need of greater attention to hygienic aspects in order to reduce health risks, deriving from an uncorrected application of the laws, and to provide a greater comfort to the users of swimming pools.

Rat renal and plasma prorenin are activated in vitro by different mechanisms.

The aim of the present study was to purify and identify a plasma protein fraction (PreR-Co) involved in renal prorenin activation and to explore its capacity to process plasma prorenin. PreR-Co was obtained from plasma as a single electrophoretic band by (NH(4))(2)SO(4) precipitation, Sephacryl S-200 HR gel filtration, anti-rat albumin immunoaffinity, and ion-exchange chromatography. The amidase, esterase, and kallikrein activities of PreR-Co were studied, as was its N-terminal amino acid sequence. Rat kidney extract or plasma (normal or previously treated with acid to pH 2.8) were incubated with PreR-Co for 15 minutes at 37 degrees C. Renin concentration was measured by incubation with homologous angiotensinogen. The same protocol was repeated with samples activated by trypsin. The N-terminal amino acid sequence was IIGGSMDAKGSFP, which had a homology of 90% with the beta-chain of haptoglobin, 69% with serine-proteases, and 65% with kallikreins. The renin concentration in rat kidney extract was 34+/-4 ng of angiotensin I (Ang I). mg of tissue(-1). h(-1). After PreR-Co or trypsin treatments, renin concentrations were 211+/-7 and 110+/-11 ng of Ang I. mg of tissue(-1). h(-1), respectively. The plasma renin concentration in normal plasma was 67.6+/-13.3 ng of Ang I. mL(-1). h(-1), and no significant difference was observed after PreR-Co treatment. However, a significant increase (202.8+/-7.8 ng of Ang I. mL(-1). h(-1); P<0.01) was found after trypsin treatment. The isolated PreR-Co acts on renal prorenin but not on plasma prorenin. These results suggest that active renin is processed in the kidney by a circulating enzyme that may have a role in the regulation of circulating renin.

A renin-like enzyme in rat luteal tissue: evidence of local synthesis and its regulation during pregnancy.

Changes in the concentration of a renin-like enzyme were studied in androgenized rats in which a single luteal phase was induced by the administration of chorionic gonadotrophin. A significant increase in the luteal renin-like enzyme (RLE) concentration was found between the youngest corpora lutea (48 h old) and the oldest one studied (6 days old). The luteal RLE content varied independently of changes in plasma renin concentration. These results suggest that this enzyme was produced locally. The lack of correlation between the luteal RLE and plasma prolactin supports our previous observation that the changes in luteal renin concentration appear not to be prolactin-dependent. Furthermore, the suckling-associated hormones appear not to be related with the regulation of luteal RLE concentration, since the values were not modified in androgenized maternal rats which were suckling when compared with the controls. Changes in luteal renin concentration were also studied during pregnancy. A significant increase was found a few hours after a fertile mating which reached a peak on day 1 of pregnancy, followed by a rapid decrease to low levels throughout the remainder of the pregnancy. Because the renin-angiotensin facilitates angiogenesis, luteal renin may act as an angiogenic factor, stimulating blood vessel growth in the corpora lutea. An alternative hypothesis is that the increase in RLE could be a trigger for calcium flux redistribution and steroid biosynthesis.

Cyclical changes in plasma renin during the oestrous cycle in the rat: synchronized effect of oestrogen and progesterone.

The aim of the present work was to study the relationship between sex hormones and plasma renin levels during the oestrous cycle in a Wistar-derived rat strain. Plasma renin activity (PRA) as well as a plasma renin concentration (PRC) were increased during the day of oestrus in rats with controlled 4-day oestrous cycles. This increase in PRA and PRC was not found when rats were ovariectomized on dioestrus day 2 and samples measured on the expected day of oestrus. The increase in PRA and PRC was not found when normal cyclic rats were treated with either tamoxifen or the progesterone receptor blocker RU 38486. Treatment with progesterone at pro-oestrus after ovariectomy on dioestrus day 2 partially increased the PRA and PRC when compared with the values found during the day of oestrus in control rats. The combined treatment of ovariectomized rats on dioestrus day 2 with oestrogen and progesterone restored the normal increase in PRA and PRC values on the expected day of oestrus. We therefore postulate that the sodium diuresis promoted by progesterone may be modulated by the previous peak of oestrogen. However, stimulation of extrarenal sources of renin cannot be excluded nor can an involvement of inactive precursors of renin in the fluctuations of active renin that occur during the oestrous cycle. No important change in plasma renin substrate (PRC) was observed during the oestrous cycle. PRA, PRC and PRS were determined every 4 h during the 4-day oestrous cycle. Our results clearly show a rhythmic variation in PRA and PRC which increases during the day of oestrus with a peak at 06.00 h.(ABSTRACT TRUNCATED AT 250 WORDS)

A renin-like enzyme in luteal tissue.

The aim of this study was to identify immunologically and biologically a renin-like enzyme (RLE) in rat corpora lutea (CL). The biological activity of partially purified extracts of CL was tested in vivo by injection into anesthetized pentolinium-treated rats, obtaining a pressor response similar to renal renin. The enzyme activity in vitro was inhibited to about 50% by pretreatment with a specific antibody against renal renin. When the extracts were incubated with angiotensinogen, the product was inhibited mainly by angiotensin I antibody. The fact that there was no change in RLE content in 24 or 48 h nephrectomized rats, suggested the idea of a local production rather than an active blood renin sequestration.

Half-life of circulating renin under different experimental conditions.

The half-life of circulating renin was studied in normal rats and in rats with a single kidney that was ischemic. The resulting disappearance curve represented the sum of two exponentials. The average half-life of the fast component was 11.5 minutes for normal rats, 11 minutes for rats with mild renal ischemia, and 8 minutes for rats with severe renal ischemia. The mean half-life of the slow component was 67 minutes in normality, 84 minutes in mild ischemia, and 121 minutes in severe ischemia. Also, the calculated proportion of the slower component was different for each group--60.3% in normality, 68.2% in mild ischemia, and 82.2% in severe iischemia. The results suggest that more than one kind of renin may be produced and released by the kidney, and also that renal ischemia may modify the normal metabolism of renin.

Central and peripheral diaphragmatic fatigue in loaded normal and vagotomized dogs.

Severe inspiratory elastic load terminated by respiratory arrest (RA) was studied in 24 anesthetized dogs (group 1, normal: n = 14; group 2, vagotomized: n = 10). The peripheral and central components of the decrease in diaphragmatic force generation and the events preceding RA were studied. We measured stimulated tetanic transdiaphragmatic pressure (Pdi), single twitch compound action potentials, integrated diaphragmatic electromyographic activity (iEMGdi), respiratory frequency (f), inspiratory time, inspiratory drive, overall diaphragmatic activation, and Pdi single twitch superimposed over peak Pdi. Imposed target pressure was -68.8 +/- 4.37 cmH2O for group 1 and -70.9 +/- 4.19 cmH2O for group 2, and the tension-time index of the diaphragm was the same for both groups (0.22 +/- 0.010). During load, 1) f increased in group 1 from 25.4 +/- 1.33 to 41.3 +/- 4.66 cycles/min, and tachypnea was prevented by vagotomy; 2) twitch occlusion persisted until RA and compound action potentials did not change; 3) iEMGdi and inspiratory drive increased and remained high until RA; 4) overall diaphragmatic activation increased 514 (group 1) and 260% (group 2) and then decreased to 228% of the basal value 10 s before RA in group 1 because of a fall in f; and 5) after RA, Pdi stimulated at 60 Hz fell to 39 (group 1; P < 0.0025) and 51% (group 2; NS with group 1) of the basal value. In summary, 1) peripheral fatigue developed without transmission failure; 2) diaphragmatic activation remained maximal until RA; 3) the fall in f appeared as a preterminal event only in group 1; and 4) vagus nerves are necessary for load-induced tachypnea.

Californian hybrid zone between Culex pipiens pipiens and Cx. p. quinquefasciatus revisited (Diptera:Culicidae).

Phallosome morphology (DV/D ratio) and allozyme variation were used to reexamine the transition from Culex pipiens pipiens L. to Cx. p. quinquefasciatus Say, detected in California from the northern Central Valley to the Mexican border of the United States of America. Significant deficiency of heterozygotes was observed at the diagnostic locus Mdhp-2 in populations from the central part of the hybrid zone. Long tails of introgression were detected: populations from both north and south ends of the transect were not genetically pure Cx. p. pipiens or Cx. p. quinquefasciatus, respectively, as previously considered, but included approximately 5% introgressed individuals. A narrow reversed cline from the Delta area into the Sacramento Valley, characterized by increasing frequencies of Cx. p. quinquefasciatus alleles proceeding to the north, was confirmed. Both these cline appear to be related mainly to temperature gradients. Over the last 50 yr, an increase in the proportion of Cx. p. pipiens DV/D phenotypes was detected proceeding north to south along the main latitudinal cline, as well as in the narrow reversed cline. Accordingly, the center of the main latitudinal hybrid zone has apparently moved approximately 100 km to the south. This phenomenon is only partially paralleled by the differentiated locus Pgm of the 3 for which comparison was possible. Similarities to and differences from previous studies are discussed, also in relation with comparable data from another hybrid zone between Cx. p. pipiens and Cx. p. quinquefasciatus recently detected in Madagascar. Hybrid index scores based on differentiated allozymes and the diagnostic locus Mdhp-2 prove to be better descriptors than the DV/D ratio of hybridization and introgression occurring between Cx. p. pipiens and Cx. p. quinquefasciatus. This seems to be caused mainly by the influence of temperature on male genitalia development, and the weaker association found between genetic markers and DV/D phenotypes in hybrid populations.