Middlebox Research Articles

A Vision of the Next Generation Internet: A Policy Oriented Perspective

The host centric design of the current Internet does not recognize data and end-users as integral entities of the system. The first generation of Internet has been very successful and yet business, organizations, governments are finding it difficult to enforce their policies on their networks with the same ease that they do other methods of communications and transport. Ad-Hoc solutions e.g. firewalls, NAT, middle boxes etc, that tries to mitigate these issues end up providing localized myopic fixes which often hurt the basic underlying principles of the original design. The current Internet usage is “data centric” as evidenced by the popularity of the peer-to-peer applications. Data centric view abstracts a data requestor from having to know where the data comes from. We envision the future internet to be a dynamic, heterogeneous, secure, energy efficient omnipresent network flexible enough to support innovations and policy enforcements both at the edge and the core. The first step towards the next generation is the redesign of naming and name binding mechanisms. We, therefore, propose a Policy Oriented Network Architecture (PONA) and an abstract two part protocol stack with a virtualization layer in between. PONA provides a generic architecture which allows us to implement datacentric, host-centric, and user-centric Internet architecture. We also introduce the concept of generalized communication end-points – hosts, users, data/services, instantiate the ideas with the Mapping and Negotiation layer and provide an integrated framework for the next generation Internet. Both new Internets hope to develop new, faster technologies to enhance research and communication, and it is expected that both projects will eventually improve the current commercial Internet.

Force generated by actomyosin contraction builds bridges between adhesive contacts

Extracellular matrices in vivo are heterogeneous structures containing gaps that cells bridge with an actomyosin network. To understand the basis of bridging, we plated cells on surfaces patterned with fibronectin (FN)-coated stripes separated by non-adhesive regions. Bridges developed large tensions where concave cell edges were anchored to FN by adhesion sites. Actomyosin complexes assembled near those sites (both actin and myosin filaments) and moved towards the centre of the non-adhesive regions in a treadmilling network. Inhibition of myosin-II (MII) or Rho-kinase collapsed bridges, whereas extension continued over adhesive areas. Inhibition of actin polymerization (latrunculin-A, jasplakinolide) also collapsed the actomyosin network. We suggest that MII has distinct functions at different bridge regions: (1) at the concave edges of bridges, MIIA force stimulates actin filament assembly at adhesions and (2) in the body of bridges, myosin cross-links actin filaments and stimulates actomyosin network healing when breaks occur. Both activities ensure turnover of actin networks needed to maintain stable bridges from one adhesive region to another.

Host Identity Protocol (HIP): Connectivity, Mobility, Multi-Homing, Security, and Privacy over IPv4 and IPv6 Networks

The Host Identity Protocol (HIP) is an inter-networking architecture and an associated set of protocols, developed at the IETF since 1999 and reaching their first stable version in 2007. HIP enhances the original Internet architecture by adding a name space used between the IP layer and the transport protocols. This new name space consists of cryptographic identifiers, thereby implementing the so-called identifier/locator split. In the new architecture, the new identifiers are used in naming application level end-points (sockets), replacing the prior identification role of IP addresses in applications, sockets, TCP connections, and UDP-based send and receive system calls. IPv4 and IPv6 addresses are still used, but only as names for topological locations in the network. HIP can be deployed such that no changes are needed in applications or routers. Almost all pre-compiled legacy applications continue to work, without modifications, for communicating with both HIP-enabled and non-HIP-enabled peer hosts. The architectural enhancement implemented by HIP has profound consequences. A number of the previously hard networking problems become suddenly much easier. Mobility, multi-homing, and baseline end-to-end security integrate neatly into the new architecture. The use of cryptographic identifiers allows enhanced accountability, thereby providing a base for easier build up of trust. With privacy enhancements, HIP allows good location anonymity, assuring strong identity only towards relevant trusted parties. Finally, the HIP protocols have been carefully designed to take middle boxes into account, providing for overlay networks and enterprise deployment concerns. This article provides an in-depth look at HIP, discussing its architecture, design, benefits, potential drawbacks, and ongoing work.

PART 3 New Experiments Three Factors On The Box plot, Box notch & Outlier Values

New two experiments of the three factors, in this study were constructed to investigate the effects, of the fixed variations to the box plot on subjects' judgments of the box lengths. These two experiments were constructed as an extension to the group B experiments, the ratio experiments the experiments with two variables carried out previously by Hussin, M.M. (1989, 2006, 2007). The first experiment box notch experiment, and the second experiment outlier values experiment. Subjects were asked to judge what percentage the shorter represented of the longer length in pairs of box lengths and give an estimate of percentage, one being a standard plot and the other being of a different box lengths and also varying with respect to other elements such as, box width & box notch or box width & outlier values. When Hussin, M.M. (1989) suggested in the future research points (1, 2, 3), can take account of wider range of the variables levels and the changing length of the standard box plot effects on the subjects' perception of the box length and further investigations could be made into variations such as box notch with box length; box notch with box length; whisker length, and also outlier values with these variations. However, both experiments were used the stander box length as the middle box length levels were not used in the experiments. The results of these two experiments suggest that these variations effected the subjects' perception of box length, as a results of the interactions between box plot features by creating visual illusions as which effect the subjects ability to accurately judge box length, both experiments were run in statistics department, Baghdad University.

PART 2 An Experiment on the Box plot

Abstract
 These experiments seek to investigate the effects of the fixed variations to the basic box plot on subjects' judgments of the box lengths. The study consists of two experiments, were constructed as an extension to the experiments carried out previously by Hussin, M.M. (1989, 2006). Subjects were asked to judge what percentage the shorter represented of the longer length in pairs of box lengths and give an estimate of percentage, one being a standard plot and the other being of a different box length and also varying with respect to other elements such as, box width or whisker length. When he (1989) suggested in the future research points (1, 2), the changing length of the standard box plot effects on the subjects' perception of the box length. However, both experiments were used the stander box length as the middle box length levels in the experiments. The results of these two experiments indicated that these variations effected the subjects' perception of box length. we thought that the effect in the subjects perception of these variations it might be that the subjects were affected by the visual illusion effects as Cleveland et al (1987) accepted in their replies to the comments on their work, as a results of the interactions between box plot features as which effect the subjects ability to accurately judge box length and the effects differed between variations, both experiments were run in statistics department, Baghdad University.

The Mechanism of Magnetic Interaction in Spin‐Ladder Molecular Magnets: A First‐Principles, Bottom‐Up, Theoretical Study of the Magnetism in the Two‐Legged Spin‐Ladder Bis(2‐amino‐5‐nitropyridinium) Tetrabromocuprate Monohydrate (Eur. J. Inorg. Chem. 23/2005)

AbstractThe cover picture shows the properties of the antiferromagnetic molecular spin‐ladder built by combining the 5NAP+ diamagnetic cations and the CuBr42− radical anions. The upper left box shows the structure of the two ions, the middle box its magnetic topology (the weakly interacting two‐leg ladders are clearly marked), while the lower box shows the experimental and computed magnetic susceptibility curves. Details are discussed in the article by M. Deumal, J. J. Novoa et al. on p. 4697 ff.

Doesn’t see, doesn’t know: is anticipatory looking really related to understanding or belief?

Clements and Perner (Cognitive Development, 9 (1994), 377–397) reported that children show understanding of a story character’s belief in their anticipatory looking responses before they show this in their answers to test questions. According to Clements and Perner the anticipatory looking responses provide evidence of implicit understanding of belief. This paper examines the possibility that the anticipatory looking measure is indicative of (a) children using a seeing = knowing rule, i.e. children linking not seeing with ignorance rather than a sensitivity to belief, or (b) a tendency to associate the protagonist with the left‐hand container. Thirty‐two children aged between 2 years 11 months and 4 years were told a false belief story similar to that used in Clements and Perner (1994) except that three containers were used instead of two. The protagonist first looks inside the middle box but then puts the object in the left‐hand box. In his absence, a second character moves the object unexpectedly to the right‐hand box. If children’s anticipatory looking was based on sensitivity to belief then they should have looked clearly to the left‐hand box. If it was based on an association bias or sensitivity to the character not knowing then they should have looked equally to the left‐hand and middle boxes. The results were consistent with the former prediction suggesting that children’s anticipatory looking responses may indeed be governed by an implicit sensitivity to belief.

Isolation and Characterization of the Rat Prolactin-Releasing Peptide Gene: Multiple TATA Boxes in the Promoter Region

The prolactin-releasing peptide (PrRP) gene is a novel bioactive peptide expressed in very restricted regions in the brain. To explore the molecular mechanism of PrRP gene expression, we cloned and characterized the gene and its promoter region. The gene spans approximately 2.4 kb and contains three exons and two introns. 3′RACE analysis showed that a polyadenylation signal 103 bp downstream from the stop codon was functional. Primer extension analysis indicated three transcriptional start sites (TSSs) 92, 199, and 325 bp upstream from the translational start site. Interestingly, in addition to the putative binding sites for SP1-1, AP-2, and Oct-2A, three characteristic TATA boxes were identified close to these TSSs. Transient transfection study using a series of deletion mutants revealed that the middle TATA box is important for the promoter activity. Furthermore, the cloned 1.6 kb promoter region was active only in neuron- and pituitary-derived cell lines, and the promoter region −1600∼−800 bp worked as a negative regulatory element. We demonstrated for the first time, the genomic organization and promoter function of the PrRP gene, and this knowledge will facilitate elucidation of transcriptional control of the PrRP gene.

Rupture characteristics of the three M ∼ 4.7 (1992–1994) Parkfield earthquakes

Slip on the San Andreas fault was determined for three M ∼ 4.7 earthquakes using a tomographic inverse system [Beroza and Spudich, 1988] to invert seismic source time functions (STFs) from S waves. STFs were obtained by deconvolving mainshock accelerograms by those from collocated smaller earthquakes. Accelerograms were from the U.S. Geological Survey Parkfield Small Aperture Array (UPSAR) and from a distributed array of digital accelerometer stations at Parkfield. Eight or nine STFs are used in each of the three inversions. STFs are typically symmetrical pulses with a duration of about 0.3–0.5 s. In the inversion, mainshock rise time was set to 0.05 s, and we allowed the rupture time to vary slightly from a constant rupture velocity of approximately 0.85β. Rupture for all three events, which are located in or close to the Middle Mountain preparation zone or box (MMB), quickly reaches a local maximum in slip and then propagates outward to peaks, ridges, or plateaus in the slip distribution. Slip for the October 20, 1992, event (located just inside the southern edge of the MMB) propagates from an initial spike north and updip along a curving ridge for about 2 km. The initial spike continued to grow in the November 14, 1993, event (located north of the October 20, 1992, event just beneath the hypocenter of the 1966 Parkfield earthquake), which shows little directivity, although there is a smaller patch of slip updip and to the south. In contrast, rupture for the December 20, 1994, event (located just south of the October 20, 1992, event) propagated north and slightly updip, creating a rough plateau in slip a few kilometers wide on a side. Directivity for this event also is to the north. Directivity for all three events points in the approximate direction of the 1966 hypocenter. Small pulses, which comprise a coda, are found on the STFs for several seconds after the initial impulsive event. Several tests based on the assumption that the average of all STFs from UPSAR for each event is an estimate of the true slip at the source suggest that the codas in the STFs are S waves from a long‐duration source rather than uncorrected site response. An initiation phase is found on the array average for the November 14, 1993, and December 20, 1994, events. These precursory phases are the result of a spike in slip at the hypocenter. A value of 2.4–4 mm is obtained for Dc, the slip‐weakening distance, by interpreting the initial spike as a critical patch. The few aftershocks for the October 20, 1992, event are distributed to the north and updip of the mainshock, but the November 14, 1993, event had a strong burst of aftershock activity that propagated to the north of its hypocenter at roughly the same depth. Aftershocks of the December 20, 1994, event are mostly updip. The November 14, 1993, event had the simplest slip distribution, appeared to be the most impulsive, and had the most active aftershock sequence and the greatest depth. If the eventual Parkfield earthquake initiates near the 1966 hypocenter, then the directivity of the three events studied here will have pointed to it. However, it is certainly possible that both the initiation of characteristic Parkfield shocks and the directivity of smaller events are controlled by fault properties on a larger scale such as by fault bends or jogs.

Evaluation of hive management techniques in production of royal jelly by honey bees (Apis mellifera) in New Zealand

SUMMARYTwo hive designs and two harvesting methods were evaluated in Otago, New Zealand, for their effect on yields and quality of royal jelly, and ease of management. Royal jelly yields from a queenright hive design, in which a queen excluder partially covered with a hardboard division confined the queen to the bottom brood chamber and away from the queen cells in the middle box where royal jelly was secreted, were similar to those obtained from a queenless hive design in which the queen was removed to a nucleus box. This was despite the bees clustering around the queen cells in the queenright hive having smaller hypopharyngeal glands than those in the queenless starter hive. The queenright design is recommended because of its simplicity and ease of conversion in alternating between honey and royal jelly production. Harvesting 66 h after grafting larvae resulted in similar yields to harvesting at 72 h and 78 h, indicating that beekeepers can harvest at any time on the third day without affecting producti...

Identification of two initiator elements in the bidirectional promoter of the human dihydrofolate reductase and mismatch repair protein 1 genes.

The human dihydrofolate reductase (DHFR) gene and mismatch repair protein 1 (MRP1) genes are organized in a head-to-head configuration separated by an 90 base pair sequence. We have previously shown that as small as a 114 bp promoter sequences is sufficient for accurate and efficient initiation of divergent transcription. In this study, the mechanism of accurate transcription initiation in vivo from this short bidirectional promoter was analyzed by a newly developed highly sensitive primer extension assay. The GC boxes in the middle of this sequence were essential for bidirectional promoter activity, but not sufficient for accurate initiation. The sequences overlapping the transcription initiation sites of the DHFR and MRP1 genes were shown to function as the initiator, which directs transcription from an internal site. These initiators were strictly position dependent and were active only when located from 40 to 50 base pairs downstream from the GC box. Although there is no apparent sequence homology between two initiators, a common nuclear factor bound to these elements. Existence of two initiators located on both sides of the middle GC box seems to be the molecular basis of bidirectional activity of this short DNA sequence.

Lithologic Comparison of Two Linear Sand Ridges from Nearshore and Middle Portions of New Jersey Continental Shelf, U.S.A.: ABSTRACT

Two linear sand ridges from the nearshore and middle portions of the New Jersey continental shelf were sampled using a vibracore system and box corer. Lithologic descriptions were made of the cores based on epoxy peels, X-ray radiographs, and impregnated core slabs. The cores were sampled for grain-size analysis. Box cores sampled lithologies and relative abundance of physical and biogenic structures found in the 25 to 46 cm (9.8 to 18.1 in.) of the sediment. Bottom topographies were established using 3.5 kHz data. The nearshore sand ridge sampled (74°22^primeW, 39°19^primeN) exceeded 5 km (3 mi) in length and ranged up to 2 km (1.2 mi) in width and had a relief of 6 to 10 m (20 to 33 ft). A mid-shelf ridge (74°08^primeW, 39°09^primeN), nearly 4 km (2.5 mi) long and up to 1 km (0.6 mi) wide, with a relief of 10 to 11 m (33 to 36 ft) was also studied. The vibracores averaged 6 m (20 ft) of penetration and in excess of 95% recovery, and although partially deformed as a result of the coring procedure, revealed three general lithologic units which may be common to both ridges. At the base of many of the cores, nonskeletal mud and poorly sorted sand are present; some of the interlayered sands and muds contain laminations and abundant pebbles. Overlying this unit in the nearshore ridge is a shell-rich mud and sand interval that is for the most part massive (bioturbated). This lithology was also recovered in one core from the middle shelf ridge. C-14 dates taken from the shell-rich units indicate that the middle and nearshore ridges are of different ages. The top unit in all the cores is a fine to medium-grained here termed the ridge sand. This unit, similar in both ridges, consists of stacked beds ranging from 3 to 71 cm (1.2 to 28 in.) in thickness, and generally coarsens upward. This unit in the nearshore ridge system has a slightly coarser mean grain-size range (150 to 400 µ) than the mid-shelf ridge (130 to 350 µ). Both ridges contain some alternating laminated and nonlaminated bed sequences. C-14 dates from the ridge sand units are indecisive in establishing whether the units in the nearshore and middle shelf are time equivalent. Nearshore box cores which only penetrate the ridge sand from 25 to 46 cm (9.8 to 18.1 in.) contain well-developed ripples and cross-bedding; physical structures do inate. The middle shelf box cores are dominantly burrowed sand and are muddier than nearshore box cores. End_Page 540------------------------------ Major observations from this study are: (1) what is interpreted as the base of the nearshore ridge directly overlies skeletal rich sediments, whereas what is interpreted as the base of the middle shelf ridge directly overlies sediments without skeletal remains; (2) skeletal rich and nonskeletal lithologies are present in the relief-forming portions of the ridges; and (3) the unit, the upper ridge sand, is generally similar in character on both ridges. End_of_Article - Last_Page 541------------