Higgs physics at the CLIC electron-positron linear collider

The Compact Linear Collider (CLIC) is an option for a future [Formula: see text] collider operating at centre-of-mass energies up to [Formula: see text], providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: [Formula: see text], 1.4 and [Formula: see text]. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung ([Formula: see text]) and [Formula: see text]-fusion ([Formula: see text]), resulting in precise measurements of the production cross sections, the Higgs total decay width [Formula: see text], and model-independent determinations of the Higgs couplings. Operation at [Formula: see text] provides high-statistics samples of Higgs bosons produced through [Formula: see text]-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes [Formula: see text] and [Formula: see text] allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.

[Evaluation of bone mineral density and selected metabolic markers of bone in boys with constitutional delay of growth and puberty]

The aim of this study was to evaluate bone mineral density and some markers of bone metabolism (alkaline phosphatase activity, osteocalcin concentration, deoxypirydinoline excretion), as well as the influence of physical activity and dietary calcium supplementation on bone density and bone metabolism in boys with a constitutional delay of growth and puberty (CDGP), in relation to calendar age, bone age and pubertal stage. The study was done in 41 boys aged 8-18 years with CDGP diagnosed on the basis of family history and typical pattern of growth, with prior exclusion of hormonal and non-hormonal causes of height deficiency. According to Tanner's criteria, boys were assigned to 4 groups corresponding to 4 stages of puberty (Tab. 1). Total body (total BMD) and lumbar spine (L2L4 BMD) bone mineral density were obtained using DEXA densitometry. The activity of alkaline phosphatase (AP) and serum osteocalcin (OC) concentration served as markers of bone formation. 24-h urinary deoxypirydinoline (DPD) excretion was a marker of bone resorption. Using a questionnaire, daily dietary calcium intake and physical activity were established. A positive correlation between calendar age, total BMD and L2L4 BMD was found (R = 0.70 and R2 = 0.49; R = 0.72 and R2 = 0.51; p < 0.001, respectively). Bone age was positively correlated with total BMD and L2L4 BMD (for both correlations R = 0.68, R2 = 0.47; p < 0.001). Total BMD adjusted for calendar age revealed osteoporosis in 4 cases (9.7%), osteopenia in 19 cases (46.3%) and normal bone density in 18 cases (43.9%). After adjustment of BMD to bone age, 2 boys (4.9%) were diagnosed with osteoporosis, 9 (21.9%) with osteopenia, and 30 (73.2%) with normal bone density. L2L4 BMD adjusted for calendar age showed osteoporosis in 6 cases (14.6%), osteopenia in 21 cases (51.2%) and normal density in 14 cases (34.2%). After adjustment of BMD to bone age, 3 boys (7.3%) were diagnosed with osteoporosis, 10 (24.4%) with osteopenia, and 28 (68.3%) with normal bone density. A significant correlation between stage of puberty, total BMD (p < 0.045) and L2L4 BMD (p < 0.001) was found. Values for total BMD and L2L4 BMD in boys with CDGP in relation to pubertal stage are presented in Table 2. Mean AP activity, serum OC concentration, DPD excretion, dietary calcium intake and physical activity in boys at consecutive stages of puberty are presented in Table 3. No significant correlation between pubertal stage, markers of bone metabolism, daily dietary calcium intake or physical activity was found. The boys were next grouped according to level of physical activity: low (< 10 h/week) or high (> 10 h/week). Table 4 summarizes the results for both groups. No significant differences between the groups were found concerning the parameters studied. Two groups with a low (< 1.2 g) and high (> 1.2 g) dietary calcium intake were also formed. The results for both groups are presented in Table 5. A significant correlation between dietary calcium intake and total BMD (R = 0.34 and R2 = 0.11; p < 0.03) was revealed. On the basis of these results it can be concluded that BMD values in boys with CDGP should be adjusted for bone age, thus significantly limiting the diagnosis of osteoporosis and osteopenia. BMD values for these boys increase with consecutive pubertal stage, while markers of bone metabolism do not reveal significant abnormalities (markers of bone formation increase until stage IV, markers of bone resorption show fluctuating values).

Calcium-G protein interactions in the regulation of macrophage secretion

The interplay between activated G proteins and intracellular calcium ([Ca(2+)](i)) in the regulation of secretion was studied in the macrophage, coupling membrane capacitance with calcium-sensitive microfluorimetry. Intracellular elevation of either the nonhydrolyzable analogue of GTP, guanosine-5'-O-(3-thiotriphosphate) (GTP gamma S), or [Ca(2+)](i) enhanced the amplitude and shortened the time course of stimulus-induced secretion in a dose-dependent manner. Both the ionophore- and the stimulus-induced secretory response were abolished in the presence of guanosine-5'-O-(2-thiodiphosphate) (GDP beta S). The K(d) of Ca(2+)-driven secretion was independent of GTP gamma S concentration, whereas the K(d) of the GTP gamma S-driven response decreased from 63 to 31 microM in the presence of saturating concentrations of [Ca(2+)](i). The time course of stimulus-induced secretion was dependent upon the concentration of [Ca(2+)](i). The time course of GTP gamma S-driven secretion was concentration-independent at high levels of [Ca(2+)](i), suggesting that a calcium-dependent translocation/binding step was rate-limiting. Our data strongly support a model in which [Ca(2+)](i) and activated G proteins act independently of one another in the sequential regulation of macrophage secretion. [Ca(2+)](i) appears to play a role in the recruitment and priming of vesicles from reserve intracellular pools at a step that is upstream of G protein activation. While activated, G proteins appear to play a key role in fusion of docked vesicles. Thus, secretion can result either from activating more G proteins or from elevating [Ca(2+)](i) at basal levels of G protein activation.

[Selected markers of bone metabolism in boys with constitutional delay of growth and puberty]

The aim of the study was to determine serum concentration and urinary excretion of selected parameters of bone metabolism in boys with constitutional delay of growth and puberty (CDGP) in the relation to pubertal stages. The study group consisted of 41 boys (aged 8 to 18 yrs) with CDGP. Patients were divided on the basis of Tanner's criteria into 4 groups according to the pubertal stage. Serum alkaline phosphatase (AP) activity and serum osteocalcin (OC) concentration as markers of bone growth, as well as urinary deoxypyridinoline (DPD) as a marker of bone resorption were determined. Serum AP activity in 31 (75.6%) boys was within normal age range. Mean values of serum AP activity increased insignificantly from I to IV stage of puberty. Serum OC concentrations were normal in 33 (80.5%) patients. Eight (19.5%) boys showed decreased values of serum OC concentration. Mean OC concentration insignificantly increased with the pubertal stages. DPD urinary excretion was within normal age range in all patients and was the highest in stage III of pubertal stage. No significant abnormalities of bone metabolism parameters in boys with constitutional delay of growth and puberty were found.

Dynamics of perceptual oscillations in form vision

Certain periodic dot patterns (Marroquin patterns) generate a percept of dynamically oscillating circles, and analogous effects were explored by op artists in the 1960s. Here we show psychophysically that circles are perceived in these patterns only around specific points that are quantitatively predicted by a neural model of configural units hypothesized to reside in cortical area V4. Circles superimposed on the pattern mask perception of illusory circles. A neural model of lateral inhibitory interactions among V4 configural units showing spike-frequency adaptation quantitatively accounts for the human data. The model is consistent with ideas on the neural basis of attention in V4, and it suggests that attention may be biased via neuromodulation of slow hyperpolarizing potentials in cortical neurons.

Variations in the course of the arteria centralis longa of the anterior cerebral artery in man

The arteria centralis longa (the extracerebral course of the vessel) was studied in 20 human brains (40 hemispheres taken from adults of both sexes). Brain vessels were injected with plastogen G, dissected and etched in soda lye. Arteria centralis longa was present in 36 hemispheres, and orginated from the anterior cerebral artery in the region of the origin of anterior communicating artery in 51% of the cases, from the post-communicating (A-2) segment of the anterior cerebral artery in 44% of the cases, and from the precommunicating (A-1) segment of the anterior cerebral artery in 5% of the cases.

Variations of the anterior communicating artery

Study was performed in 30 human cadavers during autopsy. The anterior communicating artery was present in all investigated cases. In 30% of instances the artery was of diameter less than 1 mm (hypoplastic).

Local immunity in pregnant women

Immunoglobulins IgA and IgG levels and Lysozyme-activity were examined in the vaginal fluid of 70 pregnant women and 30 non-pregnant women where microbiological examinations did not detect any pathological microorganisms. To confirm the local character of immune factors produced in the female genital tract, these factors were also examined in the sera. An increase of class A immunoglobulins was noted in the vaginal fluid and examined sera. IgA/IgG ratio as well as statistical calculations confirmed the local origin of antibodies within the classes. The lysozyme activity was 10 times greater in the vaginal fluid than in the sera. Both factors are relatively simple to determine and in women with recurrent inflammatory conditions of the vaginal tract can be used as indicators of the local immunity state.