Previous Protocols Research Articles

Communication-Efficient Verifiable Data Streaming Protocol in the Multi-User Setting

Verifiable data streaming (VDS) protocols enable end users with limited storage space to continuously stream data items to an untrusted cloud server, while preserving the capacity of verifying the integrity of those retrieved data items for downstream tasks. Although there has been plenty of research around the construction of VDS, we observe that they all focus on the scenario of single-user. When deploying these VDS protocols into more common applications that involve multiple users' data (e.g., network data monitoring and stock trends analysis), the size of the proof used to prove the integrity of retrieved data items grows linearly with the number of involved users. This would bring tremendous communication overhead, especially for lightweight users. To this end, we initiate the study of VDS protocols that are suitable for multi-user (or cross-user) setting. Specifically, we first introduce a new primitive called aggregatable chameleon vector commitment (ACVC) that allows to aggregate multiple proofs from different commitments into a single proof. Then, based on ACVC, we present a communication-efficient VDS protocol for the multi-user setting. That is, when querying data items from multiple users, the size of corresponding proof is constant and independent of the number of involved users. Theoretical analysis indicates that the proposed VDS protocol outperforms previous VDS protocols in terms of communication overhead. We also implement the proposed ACVC, and conduct extensive experiments to demonstrate its practicability.

Efficient showering vaccination with a live attenuated vaccine against herpesviral hematopoietic necrosis in goldfish

Herpesviral hematopoietic necrosis caused by cyprinid herpesvirus 2 (CyHV-2) frequently affects farmed goldfish Carassius auratus and gibel carp C. auratus gibelio, leading to significant economic damage. In our previous study, a live attenuated vaccine, called the P7-P8 vaccine strain, was developed by propagating virulent CyHV-2 in two non-natural host cell lines. The vaccine demonstrated high protective efficacy in goldfish with no signs of virulence reversion. Methods that reduce the costs of the procedure, including labor costs, are warranted for the practical application of this vaccine in goldfish aquaculture. The aim of this study was to explore alternative vaccination protocols for the P7-P8 strain in goldfish. First, we tested the previous standard administration protocol which is the bath vaccination with 1: 1000 diluted vaccine cultures for 2 h. In the simple first step to reduce vaccine virus culture, we examined the bathing protocol with more-diluted virus culture (ranging from 1: 1000 to 1: 81,000). The relative percentage survival (RPS) after the virulent virus immersion challenge for 2 h at 21 days post-vaccination was remarkably decreased in a dose-dependent manner; a dilution of 1: 3000 resulted in a 19% reduction from that used in the standard bathing protocol. Therefore, alternative methods (dipping and showering vaccination protocols) were tested using a 1: 100 dilution vaccine culture (10-fold more concentrated than the standard protocol) with short exposure times. Dipping vaccination for 10 s, 1 min, 2 min, and 5 min showed sufficient RPS of 82.4%–100%. The 10 s process was repeated six times using the same vaccine solution, resulting in an RPS >89%. In the showering vaccination protocol, the vaccine solution (1: 100 dilution; 1 mL, 3 mL, or 5 mL) was showered onto 20 goldfish on a net and held for 10 s, resulting in an RPS of >89%. We selected the showering vaccination as the suitable vaccination protocol. The effectiveness of this vaccination protocol was tested using the virus challenge by employing the cohabitation method with infected fish. The results showed high protective efficacy with an RPS of 65%–100%. This study demonstrated that the showering vaccination protocol, which uses small amounts of vaccine culture and produces less waste vaccine solution with short labor time, may be considered as a suitable alternative to the standard bath method in goldfish aquaculture.

Optimization of performance of Dutch newborn screening for cystic fibrosis

BackgroundDutch newborn screening (NBS) for Cystic Fibrosis (CF) introduced in 2011 showed a sensitivity of 90% and a positive predictive value (PPV) of 63%. We describe a study including an optimization phase and evaluation of the modified protocol. MethodsDutch protocol consists of four steps: determination of immunoreactive trypsinogen (IRT) and pancreatitis-associated protein (PAP), DNA analysis by INNO-LiPA and extended gene analysis (EGA).For the optimization phase we used results of 556,952 newborns screened between April 2011 and June 2014 to calculate effects of 13 alternative protocols on sensitivity, specificity, PPV, ratios of CF to other diagnoses, and costs. One alternative protocol was selected based on calculated sensitivity, PPV and costs and was implemented on 1st July 2016. In this modified protocol DNA analysis is performed in samples with a combination of IRT ≥60 µg/l and PAP ≥3.0 µg/l, IRT ≥100 µg/l and PAP ≥1.2 µg/l or IRT ≥124 µg/l and PAP not relevant. Results of 599,137 newborns screened between 1st July 2016 and 31st December 2019 were similarly evaluated as in the optimization phase. ResultsThe modified protocol showed a sensitivity of 95%, PPV of 76%, CF to CF transmembrane conductance regulator-related metabolic syndrome/CF screen positive, inconclusive diagnoses (CRMS/CFSPID) ratio 12/1, CF/CF carrier ratio 4/1. Costs per screened newborn were slightly higher. Eleven children, of whom five with classic CF, would not have been referred with the previous protocol. ConclusionsThe modified protocol results in acceptable sensitivity (95%) and good PPV of 76% with minimal increase in costs.

Longitudinal scRNA-seq analysis in mouse and human informs optimization of rapid mouse astrocyte differentiation protocols.

Macroglia (astrocytes and oligodendrocytes) are required for normal development and function of the central nervous system, yet many questions remain about their emergence during the development of the brain and spinal cord. Here we used single-cell/single-nucleus RNA sequencing (scRNA-seq/snRNA-seq) to analyze over 298,000 cells and nuclei during macroglia differentiation from mouse embryonic and human-induced pluripotent stem cells. We computationally identify candidate genes involved in the fate specification of glia in both species and report heterogeneous expression of astrocyte surface markers across differentiating cells. We then used our transcriptomic data to optimize a previous mouse astrocyte differentiation protocol, decreasing the overall protocol length and complexity. Finally, we used multi-omic, dual single-nuclei (sn)RNA-seq/snATAC-seq analysis to uncover potential genomic regulatory sites mediating glial differentiation. These datasets will enable future optimization of glial differentiation protocols and provide insight into human glial differentiation.

Laminin fragments conjugated with perlecan’s growth factor-binding domain differentiate human induced pluripotent stem cells into skin-derived precursor cells

Deriving stem cells to regenerate full-thickness human skin is important for treating skin disorders without invasive surgical procedures. Our previous protocol to differentiate human induced pluripotent stem cells (iPSCs) into skin-derived precursor cells (SKPs) as a source of dermal stem cells employs mouse fibroblasts as feeder cells and is therefore unsuitable for clinical use. Herein, we report a feeder-free method for differentiating iPSCs into SKPs by customising culture substrates. We immunohistochemically screened for laminins expressed in dermal papillae (DP) and explored the conditions for inducing the differentiation of iPSCs into SKPs on recombinant laminin E8 (LM-E8) fragments with or without conjugation to domain I of perlecan (PDI), which binds to growth factors through heparan sulphate chains. Several LM-E8 fragments, including those of LM111, 121, 332, 421, 511, and 521, supported iPSC differentiation into SKPs without PDI conjugation. However, the SKP yield was significantly enhanced on PDI-conjugated LM-E8 fragments. SKPs induced on PDI-conjugated LM111-E8 fragments retained the gene expression patterns characteristic of SKPs, as well as the ability to differentiate into adipocytes, osteocytes, and Schwann cells. Thus, PDI-conjugated LM-E8 fragments are promising agents for inducing iPSC differentiation into SKPs in clinical settings.

Evidence of resistance to ivermectin in the gastrointestinal nematodes of horses from Mexican southeast.

Gastrointestinal nematodes (GIN) are a major impediment to breeding and exploitation of horses. Traditional control of GIN has generated resistance to main anthelmintics, including ivermectin. An analysis of five ranches with a history of IVM use was done to determine the efficacy and resistance of GIN to IVM treatment in horses from the Mexican southeast. Predesigned questionnaires were applied to collect information on previous treatment protocols. The fecal egg count reduction test (FECRT) was applied to determine resistance. Before IVM application, a McMaster test was used to diagnose GIN infection in horses, and feces cultures were done to identify L3 larvae for Strongylida eggs. Pre-treatment samples showed that 72.7% (80/110) of horses were GIN positive, with cyathostomins being the most frequent (91.8%), followed by Oxyuris equi (7.0%), Parascaris equorum (1.0%), and Strongylus vulgaris (0.2%). Based on the results, the horses at each ranch were divided in control (CG) and experimental (EG) groups with similar eggs per gram of feces (EPG). The EG (40/80) was dewormed with IVM (0.2mg/kg orally) and the CG (40/80) remained untreated. After 14days, EPG were measured, and feces cultures were done again to identify L3 larvae. After treatment of EG, 40% (16/40) of horses were positive, the most frequently identified GIN were cyathostomins (98.6%), followed by P. equorum (1.0%) and S. vulgaris (0.2%). Three of the five ranches were classified as resistant, according to the FECRT, with a percentage of reduction from 53 to 68%, all of which used IVM ≥4 times annually. This is the first evidence of resistance in cyathostomins to IVM treatment in horses from the Mexican southeast, adding to the current problem of anthelmintic resistance in equine GIN.

Multiparty semiquantum key agreement with d-level single-particle states

In this paper, we propose a three-party semiquantum key agreement (SQKA) protocol based on d-level single-particle states first, where one quantum communicant and two semiquantum communicants can generate a final shared key via the quantum channel equally. The semiquantum communicants need to perform quantum measurement operations and encode their secret keys with the qudit shifting operation. The security analysis turns out that this protocol can resist both the external attack and the participant attack. Compared with the only previous SQKA protocol within d-level quantum system (Li et al., 2020), this protocol has the following advantages: (1) it can establish a final shared key between one quantum party and two semiquantum parties; and (2) it does not employ permutation operations from the semiquantum party Finally, this protocol is extended to its counterpart of N-party.

Single‐Source Precursors for the Chemical Vapor Deposition of Iron Germanides

AbstractBinary iron‐germanium phases are promising materials in magnetoelectric, spintronic or data storage applications due to their unique magnetic properties. Previous protocols for preparation of FexGey thin films and nanostructures typically involve harsh conditions and are challenging in terms of phase composition and homogeneity. Herein, we report the first example of single source chemical vapor deposition (CVD) of FexGey films. The appreciable volatility of [Ge[Fe2(CO)8]2], [Cl2GeFe(CO)4]2 and Me₂iPr₂NHC ⋅ GeCl2 ⋅ Fe(CO)4 allowed for their application as precursors under standard CVD conditions (Me₂iPr₂NHC=1,3‐diisopropoyl‐4,5‐dimethylimidazol‐2‐ylidene). The thermal decomposition products of the precursors were characterized by TGA and powder XRD. Deposition experiments in a cold‐wall CVD reactor resulted in dense films of FexGey. During the optimization of synthetic conditions for precursor preparation the new iron‐germanium cluster Cl2Ge[Fe2(CO)8]Ge[Fe2(CO)8] was obtained in experiments with a higher stoichiometric ratio of GeCl2 ⋅ 1,4‐dioxane vs. Fe2(CO)9.

A redesigned secure and efficient data transaction protocol for mobile payment system

Generally, the secure protocol was proposed from the certificateless signature (CLS) scheme to provide the corresponding security for the actual application. However, for the previous application protocols, most of the underlying CLS schemes cannot have their claimed security, because some proposals cannot resist forgery attacks or the master secret key can be captured by the probabilistic polynomial time adversary. To further address the above problems, we take several previous CLS schemes as instances to make a detailed analysis of the causes of the above security flaws and point out that, in a secure CLS scheme, we should appropriately publish the public parameters. Based on the above analysis, we design an efficient and secure CLS scheme in this paper, and the unforgeability is proved based on the hardness of discrete logarithm complexity assumption through the Forking lemma. Compared with the existing constructions, our new proposal has advantages in communication and computation efficiency but also has higher security. Furthermore, a concrete construction of a certificateless aggregate signature (CLAS) scheme is designed with the above basic CLS scheme to realize efficient verification of multiple signatures. Finally, we further improve the key conditions that need to be paid attention to design a secure CLS scheme.

Reference Broadcast-Based Secure Time Synchronization for Industrial Wireless Sensor Networks

Security is an important factor that cannot be neglected in the design of time synchronization algorithms since industrial wireless sensor networks are prone to attacks against physical nodes and communication links. The Sybil attack is an intelligent attack with a high destructive capacity in pretending multiple identities and broadcasting illegitimate messages to destroy the network operation. Existing secure time synchronization algorithms mostly focus on distributed protocols; however, they pay less attention to Sybil attacks and centralized network time synchronization. In this paper, we propose a novel reference broadcast-based secure time synchronization (RSTS) for industrial wireless sensor networks with a time source against Sybil attacks. Different from previous protocols, in converging the network structure and the clock status, RSTS employs a public neighbor forwarding mechanism based on reference broadcast to filter the illegal time information automatically. Instead of establishing a table with timestamps of packet transmission and receipt, the least square linear regression is utilized to estimate the compensation relative to the source node with the recorded time and calculated time difference in receiving packets. The simulation results demonstrate that RSTS is resilient to Sybil attacks as well as message manipulation attacks in comparison with existing algorithms.

Enhanced differentiation of the mouse oli-neu oligodendroglial cell line using optimized culture conditions

ObjectiveOligodendrocytes (OL) are the glial cell type in the CNS that are responsible for myelin formation. The ability to culture OLs in vitro has provided critical insights into the mechanisms underlying their function. However, primary OL cultures are tedious to obtain, difficult to propagate and are not easily conducive to genetic manipulation. To overcome these obstacles, researchers have generated immortalized OL like cell lines derived from various species. One such cell line is the mouse Oli-neu line which is thought to recapitulate characteristics of OLs in early stages of maturity. They have been extensively utilized in multiple studies as surrogates for OLs, especially in analyzing epigenetic modifications and regulatory pathways in the OL lineage.ResultsIn this report we present the development of optimized culture media and growth conditions that greatly facilitate the differentiation of Oli-neu cells. Oli-neu cells differentiated using these new protocols exhibit a higher expression of myelin related genes and increased branching, both of which are defining characteristics of mature OLs, when compared to previous culture protocols. We envision that these new culture conditions will greatly facilitate the use of Oli-neu cells and enhance their ability to recapitulate the salient features of primary OLs.

An Improved Secure Authentication in Lightweight IoT

Internet of Things (IoT) has been widely accepted by users and with rapid development of cloud computing, users are able to access the IoT services in various environment, including smart home, healthcare and smart factory. However, users are insecure as their data is being transmitted via open communication channel. The previous research protocol does not resist insider attack which leads to insecure scheme. In this proposal, we propose an enhanced security measurement to resist insider attack. The proposed scheme expected to achieve security requirements and resist insider attack. The proposed scheme will be validated using the automated validation of internet security protocols and applications (AVISPA) simulation tool and we will compare the performance and security features of the existing scheme and the proposed scheme.

On the optimal resistance against mafia and distance fraud in distance-bounding protocols

Distance-bounding protocols are security protocols with a time measurement phase used to detect relay attacks, whose security is typically measured against mafia-fraud and distance-fraud attacks. A prominent subclass of distance-bounding protocols, known as lookup-based protocols, use simple lookup operations to diminish the impact of the computation time in the distance calculation. Independent results have found theoretical lower bounds 12nn2+1 and 12n, where n is the number of time measurement rounds, on the security of lookup-based protocols against mafia and distance-fraud attacks, respectively. However, it is still an open question whether there exists a protocol achieving both security bounds. This article closes this question in two ways. First, we prove that the two lower bounds are mutually exclusive, meaning that there does not exist a lookup-based protocol that provides optimal protection against both types of attacks. Second, we provide a lookup-based protocol that approximates those bounds by a small constant factor. Our experiments show that, restricted to a memory size that linearly grows with n, our protocol offers strictly better security than previous lookup-based protocols against both types of fraud.

Initiation of a Comprehensive Early Discharge Program at a Veterans Affairs Hospital.

Early discharge protocols have become a major surgical paradigm, but this protocol is not routinely used in the Veteran Affairs (VA) system. The primary objective was to demonstrate the feasibility of a comprehensive joint program (CJP) protocol, including same-day discharge, at a VA hospital. Secondary objectives are to determine whether an increase in postoperative complications, increased readmissions, and increased ER visits compared with previous management protocols occur. A retrospective review of patients undergoing primary total joint arthroplasty conducted before the initiation of CJP was compared with patients undergoing primary total joint arthroplasty conducted after the initiation of CJP. The two cohorts were subdivided further into total knee arthroplasty (TKA) and total hip arthroplasty (THA). Patients' demographics, medical comorbidities, discharge disposition, length of stay (LOS), surgery information, 30-day and 90-day postoperative complications, surgical site infections, and emergency room visits were collected and assessed with paired t -tests. A total of 200 control cases (101 TKA, 99 THA) were compared with 260 cases (165 TKA, 95 THA) in the CJP group. The mean LOS reduced from 4.38 days in the control group to 0.75 days in the CJP group ( P < 0.001), with 890 total inpatient days in the control group compared with just 200 total inpatient days with the CJP group. A total of 92 patients (34.5%) in the CJP group were discharged the same day compared with 0 in the control group ( P < 0.001). In the control group, 47.8% were discharged to rehabilitation centers compared with only 4.5% in the CJP group ( P < 0.001). The 30-day complication rate was reduced with CJP (5.6% vs. 10.3% control) ( P = 0.028). ER visits did not significantly change (8.9% control vs. 9.3% CJP; P = 0.77). Overall LOS and complication rates were reduced with the CJP, exemplifying the viability of such a protocol in the VA system. In addition, we demonstrated no increased risks accompanied with early discharge to home. This initiative can be used to reduce healthcare dollars in VA healthcare system nationally.

Decoherence of Single‐Excitation Entanglement over Duan‐Lukin‐Cirac‐Zoller Quantum Networks Caused by Slow‐Magnetic‐Field Fluctuations and Protection Approach

AbstractAtomic spin‐wave (SW) memory is a building block for quantum repeater. However, due to decoherence caused by atomic motions and magnetic‐field gradients, SW retrieval efficiency decays with storage time. Slow magnetic‐field fluctuations (SMFFs) lead to shot‐to‐shot phase noises of SWs, but have not been considered in previous repeater protocols. Here, a SW model including a homogeneous phase noise caused by SMFFs is developed, and then revealed that such phase noise induces decoherence of single‐excitation entanglement between two atomic ensembles in a repeater link. For verifying this conclusion, single‐excitation entanglement between two SWs in a cold atomic ensemble is experimentally prepared and observed entanglement decoherence induced by SMFFs. Limited by SMFFs, the evaluated lifetime of the single‐excitation entanglement over a repeater link is ≈135 ms, even if the link uses optical‐lattice atoms as nodes. Then an approach that may overcome such limitations and extend this lifetime to ≈1.7 s is presented.

Enhancing lightweight authenticated key agreement with privacy protection using dynamic identities for Internet of Drones

Authenticated key agreement for Internet of Drones (IoD) enables mobile users to remotely access a group of drones for secure and efficient services, including the transportation of supplies, the transmission of surveillance data and images, the provision of communication services, etc. Recently, several lightweight authenticated key agreement protocols were developed for IoD to address security problems of previous studies, and showed that the security of their protocols were formally proved and their protocols can resist possible attacks. However, this investigation demonstrates the security weaknesses of a previous protocol, which may lead to their scheme lacking user privacy protection, violating session key security, and unable to withstand impersonation attacks, and develops an enhanced protocol by adopting dynamic identities and ensuring message freshness. The enhanced protocol is proved the security using formal proofs and secure against possible attacks. Compared with related protocols, the enhanced protocol solves the previous weaknesses, provides more security requirements, and increased the overall performance by about 28.4%.

Occipital and parietal cortex participate in a cortical network for transsaccadic discrimination of object shape and orientation

Saccades change eye position and interrupt vision several times per second, necessitating neural mechanisms for continuous perception of object identity, orientation, and location. Neuroimaging studies suggest that occipital and parietal cortex play complementary roles for transsaccadic perception of intrinsic versus extrinsic spatial properties, e.g., dorsomedial occipital cortex (cuneus) is sensitive to changes in spatial frequency, whereas the supramarginal gyrus (SMG) is modulated by changes in object orientation. Based on this, we hypothesized that both structures would be recruited to simultaneously monitor object identity and orientation across saccades. To test this, we merged two previous neuroimaging protocols: 21 participants viewed a 2D object and then, after sustained fixation or a saccade, judged whether the shape or orientation of the re-presented object changed. We, then, performed a bilateral region-of-interest analysis on identified cuneus and SMG sites. As hypothesized, cuneus showed both saccade and feature (i.e., object orientation vs. shape change) modulations, and right SMG showed saccade-feature interactions. Further, the cuneus activity time course correlated with several other cortical saccade/visual areas, suggesting a ‘functional network’ for feature discrimination. These results confirm the involvement of occipital/parietal cortex in transsaccadic vision and support complementary roles in spatial versus identity updating.

A Fast Consensus for Permissioned Wireless Blockchains

With the wide deployment of Internet-of-Things (IoT), blockchain systems have been playing a crucial role to establish a trusted computing environment among potentially mistrusting agents without depending on a centralized server. Different from previous blockchain consensus protocols adopted in IoT, which rely on efficient and stable transmissions, in this paper, we consider how to reach blockchain consensus in wireless networks without reliable network support. Specifically, a realistic SINR model is adopted to depict the unreliable transmissions in wireless channels. Based on the SINR model, a distributed and randomized consensus algorithm is proposed to reach k-times consensus among n devices within O(k+logn) time steps with high probability. Note that the time complexity of our algorithm is asymptotically optimal since Ω(k+logn) is a lower bound to achieve k-times consensus in a distributed environment. We conduct both rigorous theoretical analysis and extensive simulations to validate our method. It is believed that our work can facilitate the implementation of blockchains in many wireless scenarios in which the reliable and fast transmissions cannot be guaranteed.

Regular routine aware routing in opportunistic mobile social networks

AbstractDue to intermittent connectivity, routing protocols in opportunistic mobile social networks (OMSN) forward messages through opportunistic contacts. Previous opportunistic routing protocols focus on the past contact history of nodes to make a forwarding decision. It was found that predicting temporally evolving contacts and communities according to different times of the day would improve the accuracy of the prediction. In this paper, a routing paradigm called RRoutine is proposed that allows message holders to exchange multiple copies of the message based on the predicted number of communities. This distribution continues until the remaining copies of the message become one. Each message holder applies either inter or intra‐community forwarding and selects a set of potential forwarders based on the prediction of future encounters in the community and an expected remaining duration between two nodes (ERIMD). The estimation of ERIMD takes into account the sequence of daily activities, the time scale of current activities, and the return time to regular meetings of the nodes. Also, unlike traditional routing, where a single forwarder is selected, a set of potential candidates is selected and prioritized according to their contact prediction, with the most likely candidate receiving the highest priority. Simulation results obtained from synthetic and real mobility data show that the proposed paper improves the performance of the system in terms of message delivery rate, throughput, and latency.

Opto-juxtacellular interrogation of neural circuits in freely moving mice.

Neural circuits are assembled from an enormous variety of neuronal cell types. Although significant advances have been made in classifying neurons on the basis of morphological, molecular and electrophysiological properties, understanding how this diversity contributes to brain function during behavior has remained a major experimental challenge. Here, we present an extension to our previous protocol, in which we describe the technical procedures for performing juxtacellular opto-tagging of single neurons in freely moving mice by using Channelrhodopsin-2-expressing viral vectors. This method allows one to selectively target molecularly defined cell classes for in vivo single-cell recordings. The targeted cells can be labeled via juxtacellular procedures and further characterized via post-hoc morphological and molecular analysis. In its current form, the protocol allows multiple recording and labeling attempts to be performed within individual animals, by means of a mechanical pipette micropositioning system. We provide proof-of-principle validation of this technique by recording from Calbindin-positive pyramidal neurons in the mouse hippocampus during spatial exploration; however, this approach can easily be extended to other behaviors and cortical or subcortical areas. The procedures described here, from the viral injection to the histological processing of brain sections, can be completed in ~4-5 weeks.This protocol is an extension to: Nat. Protoc. 9, 2369-2381 (2014): https://doi.org/10.1038/nprot.2014.161.