310 research outputs found
Private Incremental Regression
Data is continuously generated by modern data sources, and a recent challenge
in machine learning has been to develop techniques that perform well in an
incremental (streaming) setting. In this paper, we investigate the problem of
private machine learning, where as common in practice, the data is not given at
once, but rather arrives incrementally over time.
We introduce the problems of private incremental ERM and private incremental
regression where the general goal is to always maintain a good empirical risk
minimizer for the history observed under differential privacy. Our first
contribution is a generic transformation of private batch ERM mechanisms into
private incremental ERM mechanisms, based on a simple idea of invoking the
private batch ERM procedure at some regular time intervals. We take this
construction as a baseline for comparison. We then provide two mechanisms for
the private incremental regression problem. Our first mechanism is based on
privately constructing a noisy incremental gradient function, which is then
used in a modified projected gradient procedure at every timestep. This
mechanism has an excess empirical risk of , where is the
dimensionality of the data. While from the results of [Bassily et al. 2014]
this bound is tight in the worst-case, we show that certain geometric
properties of the input and constraint set can be used to derive significantly
better results for certain interesting regression problems.Comment: To appear in PODS 201
Functional recombinant antibodies against human chorionic gonadotropin expressed in plants
Single-chain variable fragments, diabodies and chimeric antibodies (mouse variable domains and human immunoglobulin constant domains) were engineered by DNA recombinant technique and expressed transiently in tobacco leaves. The plants expressed the three types of antigen-binding moieties, accurately and faithfully. The yield obtained was 32 mg, 40 mg and 20 mg respectively, per kg of wet weight of leaves. The chimeric antibody had high affinity for human chorionic gonadotropin (Ka=1.9Ă1010Mâ1). All three forms of the recombinant antibodies expressed by plants inhibited the binding of hCG to receptor on Leydig cells
A vaccine that prevents pregnancy in women
We report here results of clinical trials on a birth control vaccine, consisting of a heterospecies dimer of the beta subunit of human chorionic gonadotropin (hCG) associated noncovalently with the alpha subunit of ovine luteinizing hormone and conjugated to tetanus and diphtheria toxoids as carriers, that induces antibodies of high avidity (K(a) approximately 10(10) M-1) against hCG. Fertile women exposed to conception over 1224 cycles recorded only one pregnancy at antibody titers of > 50 ng/ml (hCG bioneutralization capacity). The antibody response declines with time; fertility was regained when titers fell to < 35 ng/ml. This study presents evidence of the feasibility of a vaccine for control of human fertility
Independent measurement of the Hoyle state feeding from 12B using Gammasphere
Using an array of high-purity Compton-suppressed germanium detectors, we
performed an independent measurement of the -decay branching ratio from
to the second-excited (Hoyle) state in . Our
result is , which is a factor smaller than the previously
established literature value, but is in agreement with another recent
measurement. This could indicate that the Hoyle state is more clustered than
previously believed. The angular correlation of the Hoyle state
cascade has also been measured for the first time. It is consistent with
theoretical predictions
Association between longer hospitalization and development of de novo donor specific antibodies in simultaneous liverâkidney transplant recipients
© 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Background:De novo Donor Specific Antibodies (DSA) are considered as a risk factor for the kidney allograft outcomes in recipients after simultaneous liverâkidney transplantation (SLKT). We hypothesized that length of hospital stay (LOS) might be associated with de novo DSA development of due to the increased likelihood of receiving blood transfusions with reduced immunosuppressive regimens. Methods: This study is a single-center, retrospective cohort study consisting of 85 recipients who underwent SLKT from 2009 to 2018 in our hospital. We divided the patients into two groups according to LOS [long hospital stay (L) group (LOS \u3e14 days) and short hospital stay (S) group (LOS â€14 days)]. Propensity score (PS) has been created using logistic regression to predict LOS greater than median of 14 days. The association between the presence of de novo DSA and LOS was assessed by logistic regression models adjusted for PS. Results: The mean age at transplantation of the entire cohort was 55.5 ± 10.1 years. Sixty percent of the recipients were male and Caucasian. Median LOS in (L) group was three-fold longer than (S) group [L: median 30 days (IQR: 21â52), S: median 8.5 days (IQR: 7â11)]. Eight patients developed de novo DSA after SLKT (9.4%), all of them were in (L) group. Longer LOS was significantly associated with higher risk of development of de novo DSA in unadjusted (OR+ each 5 days: 1.09, 95% CI:1.02â1.16) and PS adjusted (OR+ each 5 days: 1.11, 95% CI:1.02â1.21) analysis. Conclusion: Longer hospitalization is significantly associated with the development of de novo DSA in SLKT
of Struma Ovarii: A Rare Ovarian Tumor
Abstract Struma ovarii or monodermal teratoma is a specialized ovarian neoplasm which mainly constitutes mature thyroid tissue. It is a rare tumor which comprises 1% of all ovarian tumors and 2.7% of all dermoid tumors. Thyroid tissue can be observed in 5-15% of dermoid tumors but to designate the tumor as struma ovarii, it must comprise more than 50% of the ovarian tissue. This study was conducted in the Department of Pathology, Manipal Teaching Hospital in Pokhara, Nepal over a period of 10 years (Jan 2006 to Sep 2015. Age, clinical findings, preoperative imaging diagnosis, size and side of the tumor, gross and microscopic findings along with type of surgery performed are included in the study. During this 10 years period, there were 7 cases of struma ovarii with age ranging from 26 to 56 years. 2 cases had tumor on the right and 4 cases had tumor on the left side while 1 case had bilateral struma ovarii. Initial presenting symptom was palpable mass, abdominal pain and vaginal bleeding. The size of the tumor ranged from 4 to 15 cm. The capsule was smooth and cut surface shows multiloculated cyst filled with greenish to pale brown gelatinous thick fluid. Microscopic examination revealed well encapsulated tumor composed entirely of thyroid follicles. Diagnoses of struma ovarii were made in all cases. The preoperative imaging may not exactly give the diagnosis. Clinically, lesser age group was more affected and left side is more commonly involved in our series, in contrary to other literature. Out of 7 cases, bilateral struma ovarii was seen in 1 patient. No malignant features were seen in any of these cases
Ultrafast optical generation of coherent phonons in CdTe1-xSex quantum dots
We report on the impulsive generation of coherent optical phonons in
CdTe0.68Se0.32 nanocrystallites embedded in a glass matrix. Pump probe
experiments using femtosecond laser pulses were performed by tuning the laser
central energy to resonate with the absorption edge of the nanocrystals. We
identify two longitudinal optical phonons, one longitudinal acoustic phonon and
a fourth mode of a mixed longitudinal-transverse nature. The amplitude of the
optical phonons as a function of the laser central energy exhibits a resonance
that is well described by a model based on impulsive stimulated Raman
scattering. The phases of the coherent phonons reveal coupling between
different modes. At low power density excitations, the frequency of the optical
coherent phonons deviates from values obtained from spontaneous Raman
scattering. This behavior is ascribed to the presence of electronic impurity
states which modify the nanocrystal dielectric function and, thereby, the
frequency of the infrared-active phonons
Dynamical stability of infinite homogeneous self-gravitating systems: application of the Nyquist method
We complete classical investigations concerning the dynamical stability of an
infinite homogeneous gaseous medium described by the Euler-Poisson system or an
infinite homogeneous stellar system described by the Vlasov-Poisson system
(Jeans problem). To determine the stability of an infinite homogeneous stellar
system with respect to a perturbation of wavenumber k, we apply the Nyquist
method. We first consider the case of single-humped distributions and show
that, for infinite homogeneous systems, the onset of instability is the same in
a stellar system and in the corresponding barotropic gas, contrary to the case
of inhomogeneous systems. We show that this result is true for any symmetric
single-humped velocity distribution, not only for the Maxwellian. If we
specialize on isothermal and polytropic distributions, analytical expressions
for the growth rate, damping rate and pulsation period of the perturbation can
be given. Then, we consider the Vlasov stability of symmetric and asymmetric
double-humped distributions (two-stream stellar systems) and determine the
stability diagrams depending on the degree of asymmetry. We compare these
results with the Euler stability of two self-gravitating gaseous streams.
Finally, we determine the corresponding stability diagrams in the case of
plasmas and compare the results with self-gravitating systems
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