1,656 research outputs found
Resistance to Bipyridyls Mediated by the TtgABC Efflux System inPseudomonas putidaKT2440
Resistance-nodulation-division (RND) transporters are involved in antibiotic resistance and have a broad substrate specificity. However, the physiological significance of these efflux pumps is not fully understood. Here, we have investigated the role of the RND system TtgABC in resistance to metal ion chelators in the soil bacteriumPseudomonas putidaKT2440. We observed that the combined action of an RND inhibitor and the chelator 2,2'-bipyridyl inhibited bacterial growth. In addition, the deletion ofttgBmade the strain susceptible to 2,2'-bipyridyl and natural bipyridyl derivatives such as caerulomycin A, indicating that TtgABC is required for detoxification of compounds of the bipyridyl family. Searching for the basis of growth inhibition by bipyridyls, we found reduced adenosine triphosphate (ATP) levels in thettgBmutant compared to the wild type. Furthermore, the expression of genes related to iron acquisition and the synthesis of the siderophore pyoverdine were reduced in the mutant compared to the wild type. Investigating the possibility that 2,2'-bipyridyl in thettgBmutant mediates iron accumulation in cells (which would cause the upregulation of genes involved in oxidative stressviathe Fenton reaction), we measured the expression of genes coding for proteins involved in intracellular iron storage and the response to oxidative stress. However, none of the genes was significantly upregulated. In a further search for a possible link between 2,2'-bipyridyl and the observed phenotypes, we considered the possibility that the ion chelator limits the intracellular availability of metabolically important metal ions. In this context, we found that the addition of copper restores the growth of thettgBmutant and the production of pyoverdine, suggesting a relationship between copper availability and iron acquisition. Taken together, the results suggest that detoxification of metal chelating compounds of the bipyridyl family produced by other bacteria or higher ordered organisms is one of the native functions of the RND efflux pump TtgABC. Without the efflux pump, these compounds may interfere with cell ion homeostasis with adverse effects on cell metabolism, including siderophore production. Finally, our results suggest that TtgABC is involved in resistance to bile salts and deoxycholate
Physical Activity Behavior Comparisons Between Adults With and Without Type 1 Diabetes
Physical activity (PA) is a widely accepted strategy to manage chronic diseases like type 1 diabetes; however, unique PA barriers likely result in lower PA levels among person(s) with type 1 diabetes (PWT1D), compared to person(s) without type 1 diabetes (PWOT1D). The integrated theory of health behavior change (ITHBC) (i.e., knowledge/beliefs, self-regulation, and self-management) provides a helpful framework for understanding PA and other health behaviors. This research aimed to determine differences in PA between adult PWT1D and PWOT1D, and characterize their PA-related behaviors using the ITHBC. Participants (N = 90; 86.7% female, 90% white) were recruited via social media and university listserv to complete an online questionnaire. Questions addressed demographics, anthropometrics, diabetes status, and PA-related behaviors. Participants were matched for race, gender, age, and body mass index. PA and related behaviors were compared between PWT1D and PWOT1D using independent samples t-tests and chi-square-tests. No significant differences were found between PWT1D and PWOT1D for weekly minutes of moderate- or vigorous-aerobic PA, or weekly days of muscle-strengthening PA (p \u3e 0.05). Fifty-one percent of PWT1D and 53.3% of PWOT1D reported enough activity to meet PA guidelines. Almost twice as many PWT1D meeting PA guidelines reported using goal setting, a self-regulation behavior, compared to those who did not meet guidelines (82.6% versus 45.5%, p = 0.009). Targeting PA-related behaviors within ITHBC constructs may help reinforce or influence PA behaviors. These findings can inform future behavior change interventions with PWT1D that focus on educational practices for type 1 diabetes educators or healthcare providers for PWT1D so they can better aid patients
The ABC transporter family efflux pump PvdRTβOpmQ of Pseudomonas putida KT2440: purification and initial characterization
Tripartite efflux systems of the ABC-type family transport a variety of substrates and contribute to the antimicrobial resistance of Gram-negative bacteria. PvdRT-OpmQ, a member of this family, is thought to be involved in the secretion of the newly synthesized and recycled siderophore pyoverdine in Pseudomonas species. Here, we purified and characterized the inner membrane component PvdT and the periplasmic adapter protein PvdR of the plant growth-promoting soil bacterium Pseudomonas putida KT2440. We show that PvdT possesses an ATPase activity that is stimulated by the addition of PvdR. In addition, we provide the first biochemical evidence for direct interactions between pyoverdine and PvdRT
The Archive Query Log: Mining Millions of Search Result Pages of Hundreds of Search Engines from 25 Years of Web Archives
The Archive Query Log (AQL) is a previously unused, comprehensive query log
collected at the Internet Archive over the last 25 years. Its first version
includes 356 million queries, 166 million search result pages, and 1.7 billion
search results across 550 search providers. Although many query logs have been
studied in the literature, the search providers that own them generally do not
publish their logs to protect user privacy and vital business data. Of the few
query logs publicly available, none combines size, scope, and diversity. The
AQL is the first to do so, enabling research on new retrieval models and
(diachronic) search engine analyses. Provided in a privacy-preserving manner,
it promotes open research as well as more transparency and accountability in
the search industry.Comment: SIGIR 2023 resource paper, 13 page
ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄Π° Π Π§Π₯ Π΄Π»Ρ Π½Π°ΡΡΡΠΎΠΉΠΊΠΈ ΠΠΠ-ΡΠ΅Π³ΡΠ»ΡΡΠΎΡΠ°
Contrast estimation for parametric stationary determinantal point processes
We study minimum contrast estimation for parametric stationary determi-nantal
point processes. These processes form a useful class of models for repulsive
(or regular, or inhibitive) point patterns and are already applied in numerous
statistical applications. Our main focus is on minimum contrast methods based
on the Ripley's K-function or on the pair correlation function. Strong
consistency and asymptotic normality of theses procedures are proved under
general conditions that only concern the existence of the process and its
regularity with respect to the parameters. A key ingredient of the proofs is
the recently established Brillinger mixing property of stationary determinantal
point processes. This work may be viewed as a complement to the study of Y.
Guan and M. Sherman who establish the same kind of asymptotic properties for a
large class of Cox processes, which in turn are models for clustering (or
aggregation)
Π’ΡΠ°Π½ΡΠΏΠΎΡΡΠ½Π°Ρ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠ°: ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ ΡΠ°Π·Π²ΠΈΡΠΈΡ Π² ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΌ Π΄Π΅Π»Π΅
ΠΡΠΏΡΡΠΊΠ½Π°Ρ ΠΊΠ²Π°Π»ΠΈΡΠΈΠΊΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠ΅ Π² ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΌ Π΄Π΅Π»Π΅. Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· ΡΠ°ΠΊΡΠΎΡΠΎΠ², ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠ² ΠΈ ΠΏΡΠΎΠ±Π»Π΅ΠΌ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π² Π³Π»ΠΎΠ±Π°Π»ΡΠ½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠ΅ ΠΈ ΠΎΠ±ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠ΅ Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΠΉ Π°Π΄Π°ΠΏΡΠ°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π ΠΎΡΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π»ΠΈΠ±Π΅ΡΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²Π»ΠΈ. ΠΠ°Π΄Π°ΡΠΈ: β’ΠΠΎΠ½ΡΡΠΈΠ΅, Π²ΠΈΠ΄Ρ, ΡΡΠ½ΠΊΡΠΈΠΈ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ°Π΄Π°ΡΠΈ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’Π‘ΡΡΠ½ΠΎΡΡΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΡΠΎΠ±Π»Π΅ΠΌΡ ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ»ΡΡΠ΅Π²ΡΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ.
ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π² Π³Π»ΠΎΠ±Π°Π»ΡΠ½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠ΅.The final qualifying work is devoted to the study of transport logistics in the customs business.
The purpose of this work is a comprehensive analysis of the factors, mechanisms and problems of the transformation of customs logistics in the global trading system and the rationale for adapting the customs logistics of Russia in the context of the liberalization of international trade
ΠΠ»Π΅ΠΊΡΡΠΎΠΏΡΠΈΠ²ΠΎΠ΄ Π»Π΅Π½ΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠ½Π²Π΅ΠΉΠ΅ΡΠ° ΠΎΠ±ΠΎΠ³Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΉ ΡΠ°Π±ΡΠΈΠΊΠΈ
Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ-ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ° ΡΠ°ΡΡΠΎΡΠ½ΠΎ ΡΠ΅Π³ΡΠ»ΠΈΡΡΠ΅ΠΌΠΎΠ³ΠΎ ΡΠ»Π΅ΠΊΡΡΠΎΠΏΡΠΈΠ²ΠΎΠ΄Π° ΠΊΠΎΠ½Π²Π΅ΠΉΠ΅ΡΠ° ΡΠ΄ΠΎΠ²Π»Π΅ΡΠ²ΠΎΡΡΡΡΠ΅Π³ΠΎ ΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΈΠΌ ΡΡΠ»ΠΎΠ²ΠΈΡΠΌ. Π ΡΠ°Π±ΠΎΡΠ΅ Π±ΡΠ» ΠΏΡΠΎΠΈΠ·Π²Π΅Π΄ΡΠ½ ΡΠ°ΡΡΠ΅Ρ ΠΈ Π²ΡΠ±ΠΎΡ ΠΏΡΠΈΠ²ΠΎΠ΄Π½ΠΎΠ³ΠΎ Π΄Π²ΠΈΠ³Π°ΡΠ΅Π»Ρ; ΠΏΡΠ΅ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°ΡΠ΅Π»Ρ ΡΠ°ΡΡΠΎΡΡ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½Ρ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡ ΡΠΈΠ»ΠΎΠ²ΠΎΠΉ ΡΠ΅ΠΏΠΈ. ΠΠ±ΠΎΡΠ½ΠΎΠ²Π°Π½ Π²ΡΠ±ΠΎΡ ΡΠΏΠΎΡΠΎΠ±Π° ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ, ΡΠ°ΡΡΡΠΈΡΠ°Π½Ρ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ. ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΈΠΌΠΈΡΠ°ΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Ρ ΠΏΠ΅ΡΠ΅Ρ
ΠΎΠ΄Π½ΡΠ΅ ΠΏΡΠΎΡΠ΅ΡΡΡ Π² ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΡΠ΅ΠΆΠΈΠΌΠ°Ρ
ΡΠ°Π±ΠΎΡΡ.The purpose of the operation is to develop a frequency controlled electric drive of a conveyor meeting the specifications. In operation, the calculation and selection of the drive engine was made; Frequency converter, as well as defined parameters of power circuit. The choice of control method is justified, mechanical and electromechanical characteristics are calculated. By means of simulation transient processes in the main operating modes are investigated
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