Cent Of Type Research Articles

The Type 1 and Type 2 AGN dichotomy according to their ZTF optical variability

ABSTRACT The scarce optical variability studies in spectrally classified Type 2 active galactic nuclei (AGNs) have led to the discovery of anomalous objects that are incompatible with the simplest unified models (UMs). This paper focuses on the exploration of different variability features that allow to distinguish between obscured, Type 2 AGNs and the variable, unobscured Type 1s. We analyse systematically the Zwicky Transient Facility, 2.5-yr-long light curves of ∼15 000 AGNs from the Sloan Digital Sky Survey Data Release 16, which are generally considered Type 2s due to the absence of strong broad emission lines (BELs). Consistent with the expectations from the UM, the variability features are distributed differently for distinct populations, with spectrally classified weak Type 1s showing one order of magnitude larger variances than the Type 2s. We find that the parameters given by the damped random walk model lead to broader H α equivalent width for objects with τg > 16 d and long-term structure function SF∞, g > 0.07 mag. By limiting the variability features, we find that ∼11 per cent of Type 2 sources show evidence for optical variations. A detailed spectral analysis of the most variable sources (∼1 per cent of the Type 2 sample) leads to the discovery of misclassified Type 1s with weak BELs and changing-state candidates. This work presents one of the largest systematic investigations of Type 2 AGN optical variability to date, in preparation for future large photometric surveys.

Modelling the vertical structure of nuclear starburst discs: a possible source of AGN obscuration at z ∼ 1

Nuclear starburst discs (NSDs) are star-forming discs that may be residing in the nuclear regions of active galaxies at intermediate redshifts. One-dimensional (1D) analytical models developed by Thompson, Quataert and Murray show that these discs can possess an inflationary atmosphere when dust is sublimated on parsec scales. This makes NSDs a viable source for active galactic nucleus (AGN) obscuration. We model the two-dimensional (2D) structure of NSDs using an iterative method in order to compute the explicit vertical solutions for a given annulus. These solutions satisfy energy and hydrostatic balance, as well as the radiative transfer equation. In comparison to the 1D model, the 2D calculation predicts a less extensive expansion of the atmosphere by orders of magnitude at the parsec/sub-parsec scale, but the new scaleheight h may still exceed the radial distance R for various physical conditions. A total of 192 NSD models are computed across the input parameter space in order to predict distributions of a line-of-sight column density NH. Assuming a random distribution of input parameters, the statistics yield 56 per cent of Type 1, 23 per cent of Compton-thin Type 2s (CN) and 21 per cent of Compton-thick (CK) AGNs. Depending on the viewing angle (θ) of a particular NSD (fixed physical conditions), any central AGN can appear to be Type 1, CN or CK, which is consistent with the basic unification theory of AGNs. Our results show that log [NH(cm− 2)] ∈ [23,25.5] can be oriented at any angle θ from 0° to ≈80° due to the degeneracy in the input parameters.

Frying doughnuts: what can the reprocessing of X-rays to IR tell us about the AGN environment?

Active galactic nuclei (AGN) produce vast amounts of high-energy radiation deep in their central engines. X-rays either escape the AGN or are absorbed and re-emitted mostly as infrared (IR). By studying the dispersion in the ratio of observed mid-IR luminosity to observed 2–10 keV X-ray luminosity (RIR/X) in AGN, we can investigate the reprocessing material (possibly a torus or donut of dust) in the AGN central engine, independent of model assumptions. We studied the ratio of observed mid-IR and 2–10 keV X-ray luminosities in a heterogeneous sample of 245 AGN from the literature. We found that when we removed AGN with prominent jets, ∼90 per cent of type I AGN lay within a very tight dispersion in luminosity ratio (1 < RIR/X < 30). This implies that the AGN central engine is extremely uniform and models of the physical AGN environment (e.g. cloud cover, turbulent disc, opening angle of absorbing structures such as dusty tori) must span a very narrow range of parameters. We also found that the far-IR (100 μm) to mid-IR (12 μm) observed luminosity ratio is an effective discriminator between heavily obscured AGN and relatively unobscured AGN.

Titres of naturally occurring alloantibodies against feline blood group antigens in Turkish Van cats.

Seventy-eight Turkish Van cats were examined for alloantibody titres, of which 42.3 per cent had type A blood and 57.7 per cent had type B blood. No type AB cats were found. All type B cats (n = 45) showed gross evidence of agglutinating anti-A antibody, with titres ranging from 2 to 256. Sixty-seven per cent of type B cats had anti-A antibody in their plasma, with titres ranging from 8 to 32. However, 13 per cent of type B cats had plasma alloantibody titres of less than 8 and 20 per cent had titres that were higher than 32. A total of 33 type A cats were also tested for anti-B alloantibody titres in their plasma. Among the type A plasma, gross agglutination at titres of 2 and greater than 2 were determined in 24 per cent and 36 per cent of samples, respectively. Microscopic agglutination was seen in an additional 18 per cent of plasma samples. There was no significant association between gender and plasma alloantibody titres of cats (P > 0.05).

Pattern of lymph node dissemination from adenocarcinoma of the oesophagogastric junction

Abstract Background Adenocarcinoma of the oesophagogastric junction (OGJ) is rapidly increasing in incidence and the role of radical lymphadenectomy for such tumours remains controversial. The aim of this study was to identify the pattern of metastatic nodal spread by histopathological assessment of all lymph node groups retrieved from resected specimens. Methods Data were collected prospectively from patients undergoing potentially curative (R0) resection with lymphadenectomy for adenocarcinoma of the OGJ between January 1996 and May 1998. Patients with type 1 tumours (lower third of the oesophagus) underwent two-stage subtotal oesophagogastrectomy with two-tier lymphadenectomy. Patients with type 2 (gastric cardia) tumours underwent D2 total gastrectomy. At the time of surgery all lymph node groups were dissected out from the specimens, labelled and assessed by a single consultant histopathologist. Results A total of 103 patients were studied. Eleven patients were understaged before operation and were inoperable or had palliative resections. Of the remaining 92 patients, 68 had type 1 tumours and 24 had type 2 tumours. Some 2301 nodes were analysed representing a median of 27 nodes per patient (26 from the oesophagectomy group and 30 from the gastrectomy group). Over 70 per cent of all patients had lymph node metastases at the time of surgery. Some 6 per cent of type 1 tumours with lymph node metastases had dissemination in both the abdominal and mediastinal nodal tiers. The common abdominal sites were the paracardial (right, 23 of 41; left, 23 of 41) and left gastric nodes (29 of 41) whereas within the mediastinum paraoesophageal (25 of 41) and bronchial (right, seven of 41; left, six of 41) metastases were more often encountered. Type 2 tumours had positive lymph nodes most frequently in the left paracardial (nine of 16), lesser curve (11 of 16) (N1 group) and left gastric (eight of 16) (N2 group) territories. The extent of lymph node positivity correlated with the T stage and differentiation of the primary tumour, as well as the presence of perineural, lymphatic and vascular invasion (P &amp;lt; 0·05). Conclusion The high incidence and widespread dissemination of nodal metastases at the time of surgery seen with these tumours may justify the approach of systematic lymphadenectomy in the hope of performing a curative resection. The current definition of the lymph node sites in the abdominal and mediastinal tiers for type 1 tumours is based on experience with lower-third squamous carcinomas. These results demonstrate a different pattern of dissemination for junctional␣oesophageal adenocarcinomas requiring redefinition of the nodal stations to be resected in radical lymphadenectomies for such tumours.

Hearing loss and pigmentary disturbances in Waardenburg syndrome with reference to WS Type II

Thirty families in which there were 149 individuals affected by the Waardenburg syndrome (WS) were investigated for penetrance of hearing loss and pigmentary abnormalities. Twenty two families contained 89 individuals affected by WS Type II and eight families with 60 individuals affected by Type I. A bilateral symmetrical sensorineural hearing loss was found to be the most common type of hearing loss. The most frequent degree of hearing loss category was a hearing loss of > 100dB HL with no difference between syndrome types. Although there was no significant difference in the frequency of pigmentation disorders between Type I and II, considering these abnormalities as a whole, heterochromia irides was more common in Type II than Type I and other pigmentation disorders were more frequent in Type I: 62 per cent of Type I patients had more than one pigmentary defect, but only 28 per cent of Type II. Pigmentary disturbances were not significantly more frequent in the hearing impaired group than in the normally hearing group in either Type I or II when taking into account the occurrence of only one pigmentation disorder. There was a significantly higher proportion of pigmentary defects in the hearing impaired group with Type I when only those having more than one pigmentary abnormality were compared: 93.3 per cent of Type I patients and 88.5 per cent of Type II patients with a profound hearing loss had pigmentary defects. The frequency of pigmentation disorders was not greater when the hearing loss was more severe in either type. Penetrance for hearing loss and pigmentary abnormalities showed marked intrafamilial and interfamilial variation.

Origin of millisecond pulsars

The recent discovery1,2 of a 3-millisecond pulsar in the globular cluster M28 (NGC6626) suggests that a few per cent of type I super novae (of which there are several subcategories, all associated with old stellar populations) form neutron stars. If the contact-binary white dwarf model for type Is is invoked3, it seems probable that millisecond pulsars of low magnetic field would be formed in binary systems which might survive the supernova event.

Ankle fracture treated with the AO principle—an experience with 116 cases

One hundred and sixteen cases of ankle fractures were classified by the AO system and treated by open reduction and internal fixation in accordance with the AO principles. The stabilization of the lateral malleolus was emphasized. Ninety-six cases were available for functional assessment with an average follow-up of 39 months. The results were good or excellent in 90 per cent of type A fractures and in 70-80 per cent of type B and C fractures. There was no death or non-union. Local complications included wound infection (8.6 per cent) and skin necrosis (3 per cent). This study illustrates the importance of exact anatomical reduction and stable internal fixation to allow early movement after an intra-articular fracture of the ankle.

Influence of methylprednisolone on mouse alveolar type 2 cell response to acute lung injury.

To determine whether corticosteroids influence alveolar type 2 cell events after acute lung injury, we administered 30 mg/kg/day of methylprednisolone (MP) to mice at various times after a single injection of butylated hydroxytoluene (BHT). Tritiated thymidine (3H-T) autoradiographs were used to study type 2 cell proliferation and differentiation. Type 2 cell maturation was evaluated by ultrastructural analysis of lamellar body volume density and area in cells labeled with 3H-T. The BHT damaged type 1 cells and induced proliferation of type 2 cells. Sixty per cent of type 2 cells labeled with 3H-T on Day 3 differentiated into type 1 cells over a 4-day period. Lamellar body area per cell was unchanged. Early administration of MP (Days 1 and 2) inhibited type 2 cell proliferation when lung injury was mild; rebound proliferation occurred afer its discontinuation. The MP failed to inhibit proliferation when lung injury was severe. Prolonged MP administration (Days 1 to 5) resulted in greater type 2 cell proliferation, lung injury, and mortality. Late MP administration (Days 3 and 4) impaired differentiation of type 2 to type 1 cells and more than doubled lamellar body area per cell of new type 2 cells. Important interactions appear to exist between proliferation, differentiation, and maturation of alveolar type 2 cells suggesting that agents that influence one of these processes may influence all aspects of type 2 cell function.

Electronic assignment as1A′(ππ*)-1A′ of the 2980 Å system of 2-aminopyridine by rotational band contour analysis

In 2-aminopyridine the electronic origin band of the 2980 a electronic system, the longest wavelength system which has been observed, is shown to be a type B-type A hybrid band containing 55 ± 10 per cent of type A character. It follows that the electronic transition is 1 A′-1 A′ which implies a π*-π and not a π*-n electron promotion. The degree of type A character is interpreted as indicating a swing of the transition moment by 10 ± 10° from the b axis of pyridine (the in-plane axis perpendicular to C 2). Since it is expected that the first π*-π transition in pyridine has its transition moment polarized along the b axis the amino-group does not seem to perturb the pyridine transition strongly in this respect. The changes of rotational constants from the ground to the excited state in 2-aminopyridine are very similar to those in aniline and probably reflect similar changes in geometry, namely a substantial contraction of the C-NH2 bond, an opening of the internal ring angle adjacent to the substituent and...

Immunoreactive insulin, glucose tolerance, and carbohydrate inducibility in types II, 3, IV, and V hyperlipoproteinemia.

The elevation of plasma glycerides by a high carbohydrate diet (carbohydrate induction) has been systematically correlated with glucose tolerance, insulin output and ponderal index in normals and in patients with different types of hyperlipoproteinemia. Carbohydrate inducibility (ΔTG) was similar in normals and patients with Type II hyperlipoproteinemia. Delta TG was nearly always much greater than normal in Type III, and was quite heterogeneous in type IV. The scatter in ΔTG values in Type V patients was extremely great. The basal triglyceride and ΔTG were positively correlated only in Type IV. Abnormal glucose tolerance was present in approximately one third of Types II and III, one half of Type IV and 80 per cent of Type V patients. Hyperinsulinemia was present in most Type V patients, while a majority of Type II and III patients had relatively normal insulin levels. Approximately one third each of the Type IV patients had low, normal, and abnormally high insulin levels. Increasing insulin and insulinogenic indices were correlated with increased ATG in the normal, but not in any of the patient groups. In the specific groups of hyperglyceridemic patients in this study, plasma insulin levels did not appear to be a primary determinant of the degree of carbohydrate induction.

Association of centimeter-wave bursts with different spectral types of meter-wave bursts of solar radio emission

It is shown that about 40 per cent of 10.7 cm-λ bursts with peak intensities greater than 5×10−22 wm−2 (c/s)−1 are accompanied by bursts on meter waves. The percentage association increases with the peak intensity of 10.7 cm-λ bursts and attains a value of about 90 per cent when the peak intensity exceeds 1000×10−22 wm−2 (c/s)−1. The reverse association, that is, the association of a meter-λ burst with a burst on centimeter waves, is dependent on the spectral type of the meter-λ burst. The association is about 15, 40, 70, and 100 per cent for types III, V, II, and IV, respectively. The type III and type V bursts usually occur within about 1 minute and ½ minute, respectively, of the associated cm-λ burst maxima. The type II bursts occur after about 2 to 6 minutes of the associated cm-λ burst maxima. The type IV bursts in the 250 to 580 Mc/s range occur within about 4 minutes of the start of the associated cm-λ bursts. From simultaneous dynamic spectral observations in the 25 to 580 Mc/s range and single-frequency observations on 9400, 3750, 2000, and 1000 Mc/s, the average spectra of cm-λ bursts associated with different spectral types of meter-λ bursts have been studied. It is shown that cm-λ bursts associated with meter-λ type IV and type II bursts have brightness temperatures of the order of 108 and 107 deg K, respectively, and can probably be explained by synchrotron radiation of high-energy electrons. The cm-λ bursts associated with type V and type III bursts have brightness temperatures of 106 to 107 deg K in the 2000 to 9400 Mc/s range and have probably a thermal plus synchrotron origin; the 1000 Mc/s bursts have brightness temperatures higher than 107 deg K and have a nonthermal origin, probably due to plasma oscillation corresponding to type III bursts. The cm-λ bursts unaccompanied by any meter-λ burst have brightness temperatures less than 106 deg K and are believed to have a thermal origin.

Periods and Lights-Ranges of Long-Period Variable Stars.

view Abstract Citations (5) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Periods and Lights-Ranges of Long-Period Variable Stars. Merrill, Paul W. Abstract The General of Variable Stars (2d ed ; Moscow, 1938) includes data for 3196 Mira and SRa variables, of which 35 per cent have spectroscopic classifications Of classified stars, 89 per cent are of type M, 4 per cent of type S, and 7 per cent of types N, R, or C Of the better-observed M-type Mira variables, 96 per cent have bright lines The frequency-curve for variables of spectral type M shows a broad maximum at a period near 300 days, with a shoulder near 160 days. The maximum frequency for S-type variables lies near 360 days, that for carbon variables near 400 days For variables without spectral classification the maximum frequency lies near period 255 days; the difference is probably somehow connected with the fact that these variables are fainter than the others The average light-range shows a substantial increase with period from 140 to 260 days but remains nearly constant for longer periods. The average photographic light-range is smaller than the visual The average range for S-type variables is greater than that for M types, while that for the carbon variables is less Publication: The Astrophysical Journal Pub Date: March 1960 DOI: 10.1086/146841 Bibcode: 1960ApJ...131..385M full text sources ADS |

Ossification of the pubic bones at birth.

The primary ossification center for the pubic bone usually appears in the superior ramus between the fourth and sixth fetal lunar months (1, 3, 5, 10). It was detected roentgenographically in all fetuses of 340 mm. length (full term) in the series of 640 specimens reported by Francis (3). Obata (7) and Rambaud and Renault (8) described the early center as bean-shaped and usually situated near the margin of the obturator foramen. One gains the impression from the literature that the pubic cartilage is progressively ossified evenly in a single mass (Fig. 1), until the entire pubic bone is mineralized and becomes fused with the ilium above and the ischium below. Hess (5), however, describes a single instance in which two ossification centers were found in one pubic bone, early. In a study of roentgenograms of the pelves of 1,286 randomly selected newborn infants, we have found a variety of patterns of ossification of the pubic bone, with considerable differences in shape and size. We have arbitrarily classified the primary pubic ossification center at birth in three types according to its shape and extent (Fig. 2). In Type A, a single bony mass is limited to the superior ramus. Ossification does not extend as far mediad as the junction of the superior and inferior rami, so that the medial end of the ossification center is not enlarged. In Type B, a single bony mass, shaped like a dumbbell, produces an opaque strip in the superior ramus with globular expansions laterally in the body of the pubis and medially at the junction of the horizontal and descending rami. Ossification does not extend into the descending ramus. The Type C ossification center is shaped like a hook, owing to the extension of ossification beyond the junction of the rami into the descending ramus. A fourth type, Type D (Table I), includes all cases in which there are two or more ossification centers in one or both pubic bones. The demarcation between the first three types is not absolute; one type gradually merges into the next. In one premature infant there was no mineralization of the ossification center. In some cases ossification was more advanced on one side. The prevalence of the four types is shown in Table 1. As would be expected, pubic ossification is least advanced in premature infants. This is demonstrated by the significantly larger percentage of Type A (14 per cent) and smaller percentage of Type C (23 per cent) in premature, as compared to full-term infants (8 percent of Type A, 38 per cent of Type C) (P= 2.8 and 0.5 respectively). Ossification is considerably more advanced in females than in males (Table II). The only significant racial difference was a higher percentage of Type C in white males (37 per cent) as compared to Negro males (27 per cent) (P = 1.6). Continuation studies, not included in this report, showed that ossification of the pubic bone was least advanced at one year in those infants who had exhibited the most primitive ossification at birth.

INDIVIDUAL BLOOD DIFFERENCES IN MEXICAN INDIANS, WITH SPECIAL REFERENCE TO THE Rh BLOOD TYPES AND Hr FACTOR

98 Mexican Indians were tested for the blood properties A-B-O, A(1)-A(2), M-N, P, Rh'-Rh''-Rh(0)-rh, and Hr. Of the 98 Indians, 90.8 per cent belonged to group 0, 6.1 per cent belonged to A(1), and 3.1 per cent to group B. There were 61.2 per cent of type M, 3.1 per cent of type N, and 35.7 per cent of type MN. Of the 95 Mexican Indians tested with anti-P serum, 21.1 per cent were found to lack the P agglutinogen. In tests for the Rh blood types, 48.0 per cent of the Indians were found to belong to type Rh(1), 9.2 per cent to type Rh(2), 41.8 per cent to type Rh(1)Rh(2), and 1 per cent to type Rh(0). There were no bloods giving intermediate reactions. Of the 95 Indians tested for the Hr factor 44.2 per cent were found to lack this property. The reactions for the Rh blood types and Hr factor were correlated with each other and the results supported the conclusion of Race et al. that in addition to the six standard allelic genes and the so called intermediate genes, there is one or possibly two genes having the property of determining agglutinogens which react with anti-Rh' and anti-Rh'' sera, but not with anti-Hr serum. This gene (or genes) appears to be relatively common among Mexican Indians (approximately 3.3 per cent) in contrast to its rareness in white individuals.