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Background: Reference-based deconvolution estimates cell-type proportions from bulk profiles. Incomplete references are its dominant error source, yet every current remedy ends in a point estimate. We separate the operator provenance that reproduces an estimate from the information and precision that identify its target. Results: Crossing two operator histories at one reduced reference shows the estimator is not unique: 28.2% of 196,420 sample-deletion pairs differed by >0.1 total variation, and locking all learned components made paths identical. Across nine cohorts, operator history reversed 31 of 952 associations and changed significance for 126. Fixing the operator does not identify the target: observationally equivalent completions fill the open simplex and reverse retained-type rankings. Shared structure cannot tighten inherited bounds, and one to six uncalibrated views gave identical bounds. A profile library contracted estimator-output envelopes by 98.93% yet covered the full-reference effect for only 42.77% (19 wrong-sign certificates), while conditional sharp bounds stayed at [-1, 1]. Treating absolute RNA yields as exact collapsed intervals to points yet covered none of seven flow-measured targets. Contraction without coverage is false certainty. Calibrated cross-modal anchors contract width (0.51 at six types) but never validly certify a sign. Absolute quantification restores identification in principle, and a decisive sign in peripheral blood mononuclear cells requires {+/-}2.6% proxy accuracy with near-total contraction of donor-heterogeneity and dynamic-range envelopes. Conclusions: Incomplete-reference deconvolution is an identification problem, not only an estimation problem. Remedies must be judged by shrinkage, coverage, certification and false certification against held-out targets. fitdrop implements this scoring and a precision frontier for planning a decisive measurement. Update (2026-09-20): Z-Hunt-DP: accelerating thermodynamic Z-DNA prediction with dynamic programming . Z-DNA is a left-handed DNA conformation implicated in gene regulation and chromatin dynamics. Because it is usually less thermodynamically favorable than canonical B-DNA under physiological conditions, computational tools are needed to identify sequences likely to adopt the Z conformation. Legacy Z-Hunt uses a dinucleotide thermodynamic model, but searches every anti/syn assignment in a window, causing its conformation search to grow exponentially with window size. We present Z-Hunt-DP, an exact dynamic programming reformulation that preserves the original thermodynamic objective while reducing this search from O(2^d) to O(d) for a window of d dinucleotide positions. On benchmark windows, Z-Hunt-DP matched the brute-force minimum energy within numerical tolerance and achieved a 3.30x10^5 speedup at 20 dinucleotides. In an interval-localization benchmark on public human loci with experimentally mapped Z-DNA, it recovered the clipped reference interval in all 24 cases and was the most stable localizer under midpoint-core and expanded-panel analyses. Since the comparison set mi Update (2026-09-21): Show HN: A website that tracks US food prices every day. The US Department of Agriculture (USDA) publishes daily food price data for about 290 commodities on: - what growers were paid at shipping point - what buyers paid at the big city wholesale markets - what prices supermarkets advertised in their weekly ads This data comes out as dozens of separate text reports and PDFs, one per market, with no history and no way to see how prices change over time. I think this should be public data that is easy to access and understand, so I built an open-source tracker for it. Github: https://github.com/kadoa-org/food-price-monitor Comments URL: https://news.ycombinator.com/item?id=49792076 Points: 7 # Comments: 1